Fingerprints Recoverable From Cleaned Metal

dstates points out a recent article from guardian.co.uk which discusses a new method by which to recover fingerprints from metal. The method relies on corrosion caused by sweat and other biological residues on the metal's surface. Quoting: "The patterns of corrosion remain even after the surface has been cleaned, heated to 600C or even painted over. This means that traces of fingerprints stay on the metal long after the residue from a person's finger has gone. The chemical basis of the change is not yet clear, but [Dr. John Bond] believes it is corrosion by chloride ions from the salt in sweat. These produce lines of corrosion along the ridges of the fingerprint residue. When the metal is heated, for example in a bomb blast or when a gun is fired, the chemical reaction actually speeds up and makes the corrosion more pronounced."

Comments

Plastic weapons

[Anonymous Coward]

This will open up the renaissance of plastic weapons.

Re:Plastic weapons

[Anonymous Coward]

This will open up the renaissance of plastic weapons.

Or rubber grips.

Re:Plastic weapons

[shadow349]

This will open up the renaissance of plastic weapons.

Or, you know, gloves.

Re:Plastic weapons

[Kneo24]

Great, now someone will think my plastic AK-47 is real. Thanks a lot, Science!

Re:Plastic weapons

[robogobo]

just don't get the gloves "messied".

Re:Plastic weapons

[Gewalt]

Or perhaps it will cause criminals to start taking better care of their guns. A well oiled gun won't have this problem.

Re:Plastic weapons

[lazy_playboy]

or paint, presumably.

Re:Plastic weapons

[mabhatter654]

it would seem to be only circumstantial evidence though.. nearly every person who fired the gun would leave a "permanent" fingerprint. That would reduce the utility of this. I suppose what they're after is damaged metals though. Like from bombs or car crashes during persuit to be able to figure out who the guy working on the metal was when he's cinders.

Re:Plastic weapons

[nospam007]

Or perhaps it will cause criminals to start taking better care of their guns. A well oiled gun won't have this problem.

Or use stainless steel guns.

I guess the most impact could be if they could check guns from unsolved crimes from the last 50 years, if no dumbwit copa handled them without gloves that is.

Wish I could tag...

[Anonymous Coward]

Bond, John Bond.

Re:Wish I could tag...

[andy_t_roo]

on a comma separated list, wouldn't that be 2 tags?

Look out for people with white gloves

[Anonymous Coward]

They're probably criminals trying not to leave fingerprints, or Michael Jackson imitators.

Damnit!

[jawtheshark]

Damnit! I knew I should have used plastic vats to hide the bodies!

Re:Damnit!

[txoof]

Yeah, using hydrofluoric acid in the bathtub is a BAD IDEA (tm).

There's a great Scene in Breaking Bad where Jessee tries to dispose of a body in a tub using hydrofluoric acid and a disgusting cheese body gloop falls through the ceiling after the HF eats the tub.

Re:Damnit!

[Anonymous Coward]

Don't tell Hans Reiser about this.

Re:Damnit!

[PPH]

Come on! There are better ways of disposing bodies.

I wonder

[oodaloop]

how many peices of evidence for earlier crimes we can now find a print where we couldn't before? Maybe solve an unsolved crime or two, or free someone innocent? The ramifications for Iraq alone where we can match prints on IED remnants to current detainees is enough to keep me interested.

Re:I wonder

[txoof]

That's a really good question; it could be a huge boon for unsolved cases, vindicating wrongfully convicted individuals. I could also be a huge disaster for police departments. Thousands upon thousands of individuals appealing for reexamination of fingerprint evidence could swamp crime labs.

That being said, it is far worse to convict an innocent individual than to let a guilty man go free.

Re:I wonder

[Anonymous Coward]

Even better, they can collect prints on the huge stockpiles of WMD's they found and start prosecuting the new allies.

Re:I wonder

[Ucklak]

Except now we're all going to be fingerprinted so they can match these rogue fingerprints.

Re:I wonder

[Vellmont]

how many peices of evidence for earlier crimes we can now find a print where we couldn't before?

How many pieces of evidence are now ruined, because there wasn't a careful procedure followed in the chain of evidence where nobody touched it? A bullet casing or bomb fragment being criss-crossed with fingerprints isn't exactly going to make this technique any easier.

Re:I wonder

[badran]

I wonder how many fingerprints can be gathered from the remains of a pipe from some IED that was forged from junk and derby. I guess you can even find a print from a plumber who installed that pipe under the sink? Or a print of a shop keeper who was selling pipes, does it make him a bad person?? What if that person was detained for some reason?? Now with a print from a pipe that he sold is will be shipped to some remote location and,,,,,

Re:I wonder

[cluckshot]

This really drives one to another issue. The longevity of the fingerprints will remove their value. All a finger print proves is proximity. As long as a finger print is there, it proves nothing but attendance. If it was a bio-subtance it had a short life span making it not only presence in definition but also proximity in time. That made finger prints useful. The problem here is that these now become "Undated" finger prints and as such unable to be related to events which was their only value in crime ID other than to have a list of suspects. This points out the most amazing reality about the crime "proof" we see in labs today. For the most part science is destroying evidence entirely. For example: Photos once were valuable. Then retouching started. Then it went to digital where retouching could be infinite. In the end, a photo is little more than fiction in court. Sound prints same. Now we see the ability of the police to fabricate evidence against someone to fullest extent unless we all are aware of what can be done.

Re:I wonder

[couchslug]

"That being said, it is far worse to convict an innocent individual than to let a guilty man go free."

At a one/one ratio, but some friendly casualties are inevitable. We accept a certain baseline of victims and injured/KIA police as the cost of fighting crime. We also tacitly accept a few wrongful convictions...

Re:I wonder

[mikael]

Just imagine all the suspects involved with fingerprints on the brass cartridges:

1. The packing person who took the cartridges and placed them in a cardboard box.

2. The shop owner who took the cartridge out of the box to ensure it was a match with what the customer wanted.

3. The actual person who loaded the weapon.

If one fingerprint overwrites another, then it's not a problem. But what if the corrosion effect is additive and you get two patterns merged together. Would forensic experts be able to separate the two or would they get false positives with other fingerprints of innocent people?

Re:I wonder

[DarkOx]

Well this could be used to exonorate people. I mean you can make a reasonable doubt argument that.

Hey if I shoot him then you should be able to find a finger print on the gun, given the whitness says I did not ware gloves. Since you can't its resonable the whitness is lying or mistaken as they often are.

This could be a big help to the falsely accused.

Re:I wonder

[camcorder]

Even though it's wrong target, you can still trace back to see to whom shop owner sold those cartridges. With out those fingerprints it's unlikely that you will be able to identify who sold them. Checking trade records might lead you to the correct target. If you're talking about a murder case or assassination such evidence is invaluable to resolve the case. It may have more value than the actual fingerprint of the shot man.

Re:I wonder

[Anonymous Coward]

Besides the fact it would be impossible to deny you held the murder weapon unless you always have gloves on.

I'm sure a lot of crimes were committed in places the defendant said they were never at or shouldn't be and that alone could do some damage.

Let alone being able to harvest massive amounts of finger prints.

Re:I wonder

[fluch]

Would you feel the same if they would put you into jail for many years for something you haven't done?

Re:I wonder

[muridae]

"That being said, it is far worse to convict an innocent individual than to let a guilty man go free."

At a one/one ratio, but some friendly casualties are inevitable. We accept a certain baseline of victims and injured/KIA police as the cost of fighting crime. We also tacitly accept a few wrongful convictions...

When does the ratio become acceptable or unacceptable? At 10:1; 1:1; 1:1,000,000 or at either extreme, "Even the innocent should be jailed if it means we catch all the guilty people." or "The guilty should go free rather then an innocent person be jailed."

Re:I wonder

[Dorceon]

Of course the ability to find old fingerprints doesn't mean it's no longer possible to dust for prints the traditional way. You know, the way that does prove proximity in time?

Re:I wonder

[Kingrames]

That's not going to slow anyone down.

it will be easy to run an algorithm that separates one fingerprint from another - ESPECIALLY if they're blatantly differing fingerprints and one of them exists multiple times on the same object.

This would be like trying to read the stamp on an envelope after the post office has notorized it.
hardly cause for alarm.

Re:I wonder

[Digital End]

That being said, it is far worse to convict an innocent individual than to let a guilty man go free.

Tell that to the next rape victom.

Life isn't black and white, I loath short high and mighty quotes that try to paint it that way.

Re:I wonder

[rthille]

Or to the innocent man/woman locked up for life for a case of mistaken identity...

The question is, at what ratio of imprisoned innocents vs freed guilty is suffering minimized?

Re:I wonder

[cos(0)]

This question was raised and discussed by Alexander Volokh in n Guilty Men.

Re:I wonder

[txoof]

Just imagine all the suspects involved with fingerprints on the brass cartridges:

1. The packing person who took the cartridges and placed them in a cardboard box.

2. The shop owner who took the cartridge out of the box to ensure it was a match with what the customer wanted.

3. The actual person who loaded the weapon.

It's not that big of a deal to eliminate individuals once the prints have been pulled. If a crime is committed in say Idaho, and the shells were manufactured and packaged in Virginia and prints from A (criminal), B (packager), C (store owner) are pulled, it's trivial to eliminate the B set as being irrelevant.

Under normal circumstances, person B will be flagged as a suspect (because her prints are on the brass) and once it is determined that she was in Virginia when the crime was committed, she will be eliminated from the suspect list. Persons A and C are the only ones of interest left and are of course both valuable witnesses in the investigation. This is how any traditional fingerprint evidence is treated. Prints are gathered, irrelevant prints are excluded and the remaining prints are kept until they prove to be useful.

Re:I wonder

[muridae]

I wasn't claiming to be the first to bring up the question. The post I replied to said that 'we also tacitly accept a few wrongful convictions...' and I wanted to know what the poster's opinion on that N was.

Perhaps, in this time of fear mongering, it might be better to turn the question around and ask "How many innocent people should be jailed in order to catch all the guilty?" But, I wonder, how many people would recognize that an answer less then 'all' would still allow some guilty people to go free.

Re:I wonder

[Digital End]

A ratio is also black and white. I'd let loose every pot dealer in prison to prevent one innocent from going to jail, but I'd risk an innocent to keep in a rapist/murderer... and I'm sure everyone would have their own ratio.

That's the bitch about law, it's a black and white in a grey world. The trick is putting the line in the right place.

Re:I wonder

[cos(0)]

I wasn't claiming to be the first to bring up the question. Oh, I wasn't trying to put you in your place or anything like that. :) I was merely suggesting further reading to you and to the grandparent. I was very impressed by the research done in that essay -- it's quite a masterpiece.

Cheers.

Re:I wonder

[Anonymous Coward]

Well, Blackstone said 10:1... which I think is low. Benjamin Franklin said 100:1.

http://en.wikipedia.org/wiki/Blackstone%27s_formulation

Re:I wonder

[muridae]

My bad. I'm tired and read it as 'someone already answered that.'

I had heard of the essay before, but hadn't read it. It is really interesting to see some of the reasoning behind the differing values of N. I'm impressed that so many states have outlined values of N they find reasonable, but still somewhat depressed that some still find it reasonable to jail one innocent person for every guilty person just to catch the guilty one.

Re:I wonder

[Anonymous Coward]

That being said, it is far worse to convict an innocent individual than to let a guilty man go free.

As Bush, Scalia, and McCain would say, "that's pre-9/11 thinking".

Re:I wonder

[__aajfby9338]

Even though it's wrong target, you can still trace back to see to whom shop owner sold those cartridges.

Cartridges are not serialized. Even lot numbers are just marked on the carton, not on the cartridge, and any given production lot can end up being split between many, many sellers. With a shelf life measured in decades, a box of ammo might sit around on the shelf for a long, long time, and may change hands many, many times before being used. It's not even that unusual to use surplus ammo dating back to WW2 or before. A brass cartridge might have the year of manufacture stamped on the head (more likely for military ammo than for civilian ammo), and there are no markings at all applied to the projectile.

In general, it would be pretty hard to trace an arbitrary cartridge back to a particular seller or buyer without other evidence. About all that you can determine from a shell casing found at the scene of a crime would be the manufacturer, caliber, possibly the original year of manufacture (and that shell casing might have been reloaded numerous times after that), fingerprints of one or more persons who have handled it, and it may be possible to determine that it was fired in a particular firearm if (and only if) that firearm is recovered, and has not been modified, repaired, serviced, upgraded, or even fired a large number of times since that shell casing was fired in it.

You probably will not be able to trace a cartridge to a buyer or seller unless the box it came out of is also left at the scene with its credit card receipt taped to it, and even then it could be argued that a receipt indicating that particular brand and type of ammo (if the brand and type is even listed on the receipt) didn't correspond to that specific box of ammunition, and/or that the shell casing did not come from that specific box. It would be much like trying to match an individual paper napkin to a particular package, manufacturer, seller and buyer.

The FBI used to claim to be able to match a bullet to a specific manufacturing lot based on chemical analysis of the bullet's lead, but that technique has since been shown to be bogus.

Re:I wonder

[couchslug]

My "feelings" are not relevant to the facts, which I noted above. While it is the duty of law enforcement to try to avoid punishing the wrong people, it is not rational to expect that it will never happen.

I would be trying everything I could to get any wrongful conviction reversed, but I would still understand that ALL processes have an error rate which, while it can be reduced, cannot always be reduced to zero.

Re:I wonder

[Kattspya]

I will. The alternative is the possibility of being convicted on someones unsubstantiated word.

Another fairly absurd alternative is filming each and every time you fuck someone or make them sign a contract beforehand.

Re:I wonder

[mrmeval]

I'm surprised this hasn't been done before. Anyone who has handled a carbon steel framed firearm that's blued or parkerized but not painted or otherwise coated can tell you they etch pretty damn well from sweaty fingerprints. I've also seen brass shell casings with fingerprints, the prints turn black with age. There are now lacquer or polymer coated steel shell casings that would limit this effect. They're made of those materials because of cost. Many modern firearms are now coated rather than blued or parkerized though the magazines may not be. I recall seeing an antique firearm deeply etched in what could have started out being a finger print.

So this would be useful in cases where a metal object had been touched and allowed enough time for the chemical corrosion to take place. It would not be perfect as the object could have been made out of scrap and an innocent could be blamed.

Professor Anil Aggrawal http://members.tripod.com/~Prof_Anil_Aggrawal/index.html
specializes in toxicology but he might know who specializes in other aspects of forensics.
I mention his web page because he's funny and has interesting information on toxins and forensic programming.

Re:I wonder

[Anonymous Coward]

> or would they get false positives with other fingerprints of innocent people?
I don't know, but you picked the worst example possible: 1, 2, and 3 are all guilty! Not only the president who orders the atomic drop, but also the scientists who developed it and the soldiers who packed it are all burning in Hell (which I don't believe exists).

Re:I wonder

[Anonymous Coward]

Cartridges are not serialized. Even lot numbers are just marked on the carton, not on the cartridge, and any given production lot can end up being split between many, many sellers. With a shelf life measured in decades, a box of ammo might sit around on the shelf for a long, long time, and may change hands many, many times before being used. It's not even that unusual to use surplus ammo dating back to WW2 or before. A brass cartridge might have the year of manufacture stamped on the head (more likely for military ammo than for civilian ammo), and there are no markings at all applied to the projectile Military cartridges are headstamped with lot numbers.

Re:I wonder

[JesseMcDonald]

Perhaps a better question would be: are you willing to take the risk that the person you're locking up may later be proven innocent, knowing that if that happens you'll have to pay restitution for all the pain and suffering you've caused them (not to mention lost wages, etc.)?

The "correct" balance between false positive vs. false negatives is far too abstract to have any objective answer. This is a situation that calls for a feedback loop, punishment in proportion to the effects of an incorrect judgment. The standard of evidence would then take care of itself. In any event, it is only right that one make up for harm done to others, even when one thought one was doing the right thing at the time.

Re:I wonder

[garett_spencley]

"We also tacitly accept a few wrongful convictions..."

Speak for yourself.

Re:I wonder

[rthille]

Sure, but the other side of the coin may be there as well..."are you willing to let this murder/rapist/thief go to commit more crimes, create more victims" if you're wrong the other way...

Locking someone up who's innocent is bad. So is allowing a murderer to go free to kill again. I'd be nice if we could always do the right thing, but in the absence of that, I say we try for 'least suffering'.

Re:I wonder

[Fred_A]

Or to the innocent man/woman locked up for life for a case of mistaken identity... At least when someone has been locked up for life and you realise you've made a mistake, you can let him out and more or less try to make up for it (more or less since I guess you can't really).

When you've killed him, it's too late to do anything. IMO it's the single best argument against death penalty in a judicial system.

Re:I wonder

[beav007]

That only works when you know who the owner of the fingerprint is. If persons B and C are not in a fingerprint database, all you have are unmatched fingerprints on the casing, which may or may not be related to the crime.

That is WORSE than unhelpful, because you then have to try and establish that they are unrelated to the case at hand, without knowing an identity.

Re:I wonder

[drinkypoo]

You mean you haven't been already? My mom had me fingerprinted in school. Thanks, mom. Oh well, at least there's still gloves.

Re:I wonder

[keeboo]

but I'd risk an innocent to keep in a rapist/murderer

Try stating that once you're the innocent in question.

Re:I wonder

[JesseMcDonald]

Sorry, but I'm not willing to sentence someone before they commit a crime just because I see them as a potential threat. Justice requires that the punishment fit what they actually did to you, not what you or others expect them to do in the future.

Re:I wonder

[Anonymous Coward]

If the person locked up has been convicted (wrongly or not) of being a child rapist that person might not live for very long in jail.

Re:I wonder

[Headw1nd]

I'll bite, because we don't need lofty quotes to prove it's worse to convict an innocent man than let a guilty man go free, I can do it with simple algebra.

Let's take the harm suffered by letting a guilty party go free. We can call it G. We will assume this is a positive value, since I think we can agree that letting guilty people go free is harmful to society.

Now, let's take the harm of imprisoning an innocent man, which we will call I. Also positive, since putting an otherwise useful member of society in jail for no reason is something I think we'll agree is harmful.

So let's look at the harm caused by each of our actions. Letting a guilty man free is of course G, as by our previous definition. Now to calculate the value of imprisoning an innocent man, we take our value I, and add G. Why? Well, in convicting the wrong man, we have inherently allowed the guilty party to go unpunished. So we can conclude that that G is less than I + G, i.e. it is better let a guilty man go free than to punish an innocent man.

Didn't think of that, did you?

So while convicting an innocent man might give you the opportunity to go tell that rape victim, "It's ok, we got him" it's a lie, and that lie not only destroys an innocent mans life, it lets the real rapist go free.

Re:I wonder

[nospam007]

All you people having done your killings with revolvers are still safe.

Re:I wonder

[Anonymous Coward]

That was childish in the extreme. I am actually not surprised it was written by Volokh.

Re:I wonder

[syousef]

This really drives one to another issue. The longevity of the fingerprints will remove their value. All a finger print proves is proximity. As long as a finger print is there, it proves nothing but attendance.

Fingerprints are just a tool.

Traditional fingerprints can be used where time you are trying to determine if someone was there recently. This new technology may be useful in a case where the suspect claims to have no connection with a place or object. They'd need to be used more carefully and their use is limited, but this doesn't take anything away from traditional fingerprinting techniques.

Re:I wonder

[Alias777]

That being said, it is far worse to convict an innocent individual than to let a guilty man go free.

What about rampaging serial murderers that put thousands of people at risk every day they're free?

Re:I wonder

[RockDoctor]

That's a really good question; it could be a huge boon for unsolved cases, vindicating wrongfully convicted individuals.

You have someone who's been convicted of something ; you institute a second (third, or whatever) re-examination of the forensic evidence gathered at the scene using this technique (it's probably far too late to get new evidence now) ; you find no fingerprints assignable to the convicted person, and petition for a release.
The first appeal judge say to you "Absence of evidence is not evidence of absence" and toss your petition.
The second appeal judge says "So, the convict wore gloves. Film at eleven." and tosses the appeal.
The third appeal judge says "The fingerprints were on the bits of bomb casing that didn't survive, or get found.", and tosses the appeal.

Potentially, you might find enough evidence to get someone else implicated, and get them hauled in for questioning, and a new line of investigation re-opened. But that's a long, slow process, and plenty of people have died of old age waiting for vindication in those circumstances.

Re:I wonder

[vegiVamp]

> That being said, it is far worse to convict an innocent individual than to let a guilty man go free.

Ideologically speaking, this is true, and I fully agree.

However, if you convict an innocent, only he (and by extension a single family) will suffer. If you let a guilty serial killer go free, many more people and families will suffer. I don't want to go explaining the ideology of it all to those who remain behind.

Re:I wonder

[Eskarel]

Of course the other interesting thing is that for almost every innocent person who goes to jail a guilty person fundamentally goes free(if you get the wrong person for a murder then the right person goes free).

There are exceptions of course in cases where you have a group of people and you pick up one or two extras(though the odds that you'll pick up 3 people get a 4th and that 4th isn't guilty and you didn't let one of the other 3 get off easy).

So realistically the only beneficial way(read innocent men get convicted without guilty men going free or getting off easy) is basically to arrest anyone who might possibly have done it, which involves a pretty awful innocent to guilty ratio.

This is why we have the whole beyond a reasonable doubt thing, because if we put the wrong man in prison the right man goes free.

Re:I wonder

[mpe]

In general, it would be pretty hard to trace an arbitrary cartridge back to a particular seller or buyer without other evidence. About all that you can determine from a shell casing found at the scene of a crime would be the manufacturer, caliber, possibly the original year of manufacture (and that shell casing might have been reloaded numerous times after that), fingerprints of one or more persons who have handled it,

Plenty og scope for fingerprints to get on a cartridge. Especially if you were to have someone reloading cartridges someone else didn't want.

and it may be possible to determine that it was fired in a particular firearm if (and only if) that firearm is recovered, and has not been modified, repaired, serviced, upgraded, or even fired a large number of times since that shell casing was fired in it.

Recovered soon after a crime. Problem is that it would be difficult to match cartridges which have been used several times, quite possibly in different guns.

Re:I wonder

[mpe]

Now, let's take the harm of imprisoning an innocent man, which we will call I. Also positive, since putting an otherwise useful member of society in jail for no reason is something I think we'll agree is harmful.

If there was a real crime commited then jailing an innocent person means that someone who is guilty has gone free. The harm starts as soon as an innocent person is charged and any police investigation either stops completely or becomes entirely focused on finding evidence against that person. Even if they are aquitted (and the police accept the court's verdict) any subsequent investigation is likely to be a lot harder. As well as being harmful to the innocent person.

Re:I wonder

[Urkki]

I think any ratio of falsely convicted innocents is "unacceptable". Unfortunately in reality it is impossible to achieve this ratio. So there's no answer to question of what amount of innocents convicted is acceptable.

Therefore I think the better question is, when does the ratio of criminals not getting sentenced become unacceptable. IMHO that is an aswerable question, and then the ratio of innocents convicted should just be minimized given the current technology and resources.

Re:I wonder

[mpe]

Perhaps a better question would be: are you willing to take the risk that the person you're locking up may later be proven innocent, knowing that if that happens you'll have to pay restitution for all the pain and suffering you've caused them (not to mention lost wages, etc.)?

With such restitution possibly not fully making up for their loss. Especially in the UK where they are likely to have "board and lodging" deducted.

The "correct" balance between false positive vs. false negatives is far too abstract to have any objective answer. This is a situation that calls for a feedback loop, punishment in proportion to the effects of an incorrect judgment.

Very often there is no such feedback, which really should happen when people are found innocent at a trial or a case is dropped/dimissed, as well as when innocent people wind up being sentenced.
Even though someone might (eventually) be released and somewhat financially compensated. Nothing is likely to happen to those responsible. Be they police who didn't follow the rules or civilians who made malicious accusations...

Re:I wonder

[mpe]

Sure, but the other side of the coin may be there as well..."are you willing to let this murder/rapist/thief go to commit more crimes, create more victims" if you're wrong the other way...

In many cases it is the same coin. In that you are imprisoning an innocent person whilst letting a guilty person go free. The only exception would be where no crime actually happened. Which appears most likely with rape...

Re:I wonder

[Anonymous Coward]

the US does not detain iraqi/combatants for the purpose of convictions. they detain them for the purpose of gathering more intel or removing the threat from the AO.

Re:I wonder

[__aajfby9338]

Recovered soon after a crime. Problem is that it would be difficult to match cartridges which have been used several times, quite possibly in different guns.

True. The firing pin's imprint in the primer (which gets replaced with a new primer for each reload) would be valid, but things could be complicated by multiple sets of bolt face imprints on the case head.

Re:I wonder

[tmosley]

Remind me never to vote for you for any public office.

Re:I wonder

[Muad'Dave]

Question: Did she submit the prints to the police, or did she get the only copy in case you were kidnapped? Around here, the prints _only_ go the the parents to hang onto in case the unthinkable happens.

Re:I wonder

[JCSoRocks]

It could also be a huge disaster for police departments. Thousands upon thousands of individuals appealing for reexamination of fingerprint evidence could swamp crime labs. Yeah, that won't be much of a problem... they'll just ignore it. Just like they've done in the past when it's been made obvious that the state has accepted evidence presented by "experts" that actually know nothing.
This article talks a bit about what a problem it is. I don't see the specific case in it that I was looking for though - I know there was a forensic "expert" at hair and fingerprint analysis that convicted hundreds and hundreds of people and the state refused to systematically reexamine or review any of his cases.

Re:I wonder

[rthille]

Oh, I'm not advocating locking someone up before, I'm saying that when you have a suspect for a crime, there's a trade off between letting him go if he's the guilty (murderer/rapist/thief) and he kills/rapes/steals again (causing suffering among his victims), and locking him up if he's innocent (and an innocent man/woman suffers). You can guarantee that no innocent person gets locked up, by not locking anyone up, and you can guarantee no guilty person goes free by locking everyone up. The right thing is to do your best to determine if the suspect is guilty, but err on the side of innocence (I would say that because I feel that the suffering of putting an innocent in jail is greater, in general, than the suffering which would be created in the future by a guilty person going free).

Re:I wonder

[Anonymous Coward]

"We also tacitly accept a few wrongful convictions..."

Speak for yourself.

You have to accept the possibility of wrongful convictions. If you think they can be completely removed from the equation, without grave repercussions to our judicial system, then please give me some of what you're smoking.

Until then, we'll speak for you, too.

Re:I wonder

[phr1]

Your post raises the question of what happens if someone thinks I is negative.

Just because someone isn't breaking laws doesn't mean you necessarily think their presence in society is useful. In that case the obvious desired outcome is to round up the guilty and innocent alike from the "useless" part of the population, which means anyone from the wrong ethnic or religious group, political dissenters, people who voted for the wrong party, computer geeks who ask too many questions, etc. So, I think trying to resolve this type of question by cost/benefit analysis is a big mistake. While you and I hopefully think of rounding up the innocent as a cost, someone else may see it as a benefit.

In the USA, jurors determine guilt by a "reasonable doubt" standard which explicitly makes some mistakes in both directions, but erring more on the side of acquitting the guilty rather than convicting the innocent.

Re:I wonder

[Digital End]

Try stating that when you're the one raped and murdered.

Re:I wonder

[Digital End]

Well spoken.

However, you're not factoring in F, the number of additional guilty that are taken in due to the widened criteria.

And also, by your math, it is best to free everyone to remove any chance of the innocent going to jail. Who knows, that confessed serial killer might have been covering for the real killer.

Re:I wonder

[Headw1nd]

That is a very, very good point.

Re:I wonder

[Headw1nd]

You don't seem to be grasping the math very well. There is no upside to freeing guilty man by himself. That is harm G. There is no upside to keeping an innocent man in jail. That is harm I, plus harm G. But if you had a choice between freeing a guilty man and a innocent man together, or keeping them both in jail, assuming they were convicted of the same crime, freeing them both would be better. The harm would be G, vs. G+I. So unless the prisons are currently full of innocent men and guilty men in equal measure, then I would suggest keeping the doors shut for now.

I'm unsure why you have this idea that the best way for the justice system to work is to convict innocent men. Justice is best served by strong police work, informed juries, and competent legal counsel on both sides. Simply convicting someone every time there's a crime, in whatever way possible, is not justice, and isn't the way to reduce crime.

Too Bad Fingerprinting is Useless

[good soldier svejk]

At least as it is currently practiced.

Re:Too Bad Fingerprinting is Useless

[Kneo24]

From what I gather there, it's not the methodology that's at fault, it's human error. Perhaps they need better training? In the end I wouldn't say that what we currently have is useless, but only that we should trust those examining the fingerprints a little less, perhaps.

Re:Too Bad Fingerprinting is Useless

[dreamchaser]

Quite right, but a sensationalistic subject line such as 'Too Bad Fingerprinting is Useless' tends to attract karma.

Re:Too Bad Fingerprinting is Useless

[maxume]

And yet it is still used to convince juries.

Re:Too Bad Fingerprinting is Useless

[mikael]

You could have come up with a better webpage than that. The Shirley Mckie case is a good place to start. The original event happened in January 14th, 1997. A decade later, a public enquiry is only just about to start in September 2008. There is a Wikipedia entry

Re:Too Bad Fingerprinting is Useless

[Anonymous Coward]

The correct link is here.

Preview is your friend, take advantage of it. :-)

Re:Too Bad Fingerprinting is Useless

[pnewhook]

Is that James Baldwin the writer? Regardless, that quote makes no sense.

Re:Too Bad Fingerprinting is Useless

[Anonymous Coward]

Yes, and it made perfect sense. In the 50s and 60s Jews were just starting to be "white" in the eyes of the culture at large. By embracing this new identity middle class assimilationist Jews were leaving blacks behind politically. Many black intellectuals felt betrayed and abandoned. And many Jews agreed with them.

Re:Too Bad Fingerprinting is Useless

[pnewhook]

I don't know what that means. Fundamentally I do not agree that a religion can 'act' like a race. No race in it's entirety acts in any one manner so acting like a race is impossible.

'Acting white' or 'acting black' are nonsensical phrases.

Re:Too Bad Fingerprinting is Useless

[jericho4.0]

Are you retarded?

Re:Too Bad Fingerprinting is Useless

[Anonymous Coward]

I don't know what that means. Fundamentally I do not agree that a religion can 'act' like a race. No race in it's entirety acts in any one manner so acting like a race is impossible.

'Acting white' or 'acting black' are nonsensical phrases.

Race is a social construct. If society says Jews are a race, they are. If it says Jews are white, they are. Acting "as a white man" in this context means acting in the interests of the dominant social group to the detriment of the subordinate minorities.

Re:Too Bad Fingerprinting is Useless

[pnewhook]

No I'm not. Stop being an ass by acting American.

Portability?

[txoof]

This is some seriously cool tech. I wonder if there will be a portable method available. It sounds like it takes some wicked voltage to kick off the process, so it would work great in the lab, but not so great in the field.

This isn't even remotely a problem for bomb fragments, guns or other regularly handled objects. It becomes more of a problem for large objects attached to or part of buildings. This does not diminish the way-coolness of this discovery, however.

Wooden bat never fails

[Dan541]

I'll stick to the wood bat as weapon of choice for murder, it can easily be disposed of with fire.

Re:Wooden bat never fails

[Anonymous Coward]

Or you can do the "Terminator 2" thing. Put metal into a big melting pot.

I have never have any luck to remove my fingerprints off shiny metal surfaces when I open up electronics. :P

What happen if someone pour bleach or salt all over the metal surface (after degreasing it) ?

Re:Wooden bat never fails

[seyyah]

Good old bat, nothing beats bat.

Re:Wooden bat never fails

[Zosden]

Or chairs

Re:Wooden bat never fails

[Anonymous Coward]

Best weapon, least trace-able.

Icicle. Use it, melt it! Away washes the evidence.

Re:Wooden bat never fails

[Anonymous Coward]

Except paper.

Re:Wooden bat never fails

[Anonymous Coward]

Better weapon: Frozen lake
Just imagine finding prints.

Re:Wooden bat never fails

[Schraegstrichpunkt]

I bet an autopsy could reveal frostbite around the wound.

Re:Wooden bat never fails

[Nullav]

Wouldn't that be a given in an area full of icicles?

Re:Wooden bat never fails

[Dorceon]

Why not a frozen leg of lamb? Once the murder is done, it's a tasty treat for the officers investigating!

Re:Wooden bat never fails

[NormalVisual]

Or you could just take the simple precaution of picking up your spent cases if you're using a semi-automatic gun.

Re:Wooden bat never fails

[Antique Geekmeister]

We have an Alfred Hitchcock fan here! I've actually seen the ancient episode where the murderous wife fed the lamb to the police, investigating her home.

Re:Wooden bat never fails

[Basje]

Acually, it's a Roald Dahl story, only later filmed by Hitchcock:
http://en.wikipedia.org/wiki/Lamb_to_the_Slaughter

Until five minutes ago I didn't even know AH filmed it.

Re:Wooden bat never fails

[Dan541]

Not forgetting to put a drill down the barrel just in case they do find the gun.

Re:Wooden bat never fails

[Posting=!Working]

I'll just stick with a revolver. Unless you need to reload, there'll be no bullet casings left at the scene.

How Long Do They Have to be There

[theshowmecanuck]

How long do the fingerprints have to be on the metal to corrode it enough to get a good fingerprint from this method? For example, if the perpetrator uses a cloth to wipe the fingerprints off the metal immediately after the crime, will the metal have corroded enough to still give a fingerprint by this method? Or do the fingerprints need to be there for some time in order to corrode the metal enough to give a good print? And if they wipe the fingerprints off is there still enough residue to still corrode the metal, or will they need to wipe the fingerprints off using some sort of solvent or cleaner? etc. etc. etc. It would be interesting to here more.

Re:How Long Do They Have to be There

[Kneo24]

I couldn't really find how long the print had to be there in TFA, but it did say that once the print is on there, abrasive methods had to be used to remove it, i.e. removing a layer of the metal.

Re:How Long Do They Have to be There

[Anonymous Coward]

Dear theshowmecanuck:

You have been found guilty of future crimes for which you may commit for your desire of the knowledge of the circumvention of our new forensic techniques.

Signed, The Thought Police

Re:How Long Do They Have to be There

[Anonymous Coward]

A good print would presumably require a good surface finish, bullet casings are rolled from sheet I don't imagine you'd get a print of a knurled finish. The article says brass corrodes well, yet copper and zinc both have high resistance to corrosion -- but perhaps not so with chlorides? Furthermore water based cutting coolants are corrosive (and not everything is well cleaned after manufacture), to say nothing about objects that are chromed/lacquered for decorative or protective finish.

Re:How Long Do They Have to be There

[Feanturi]

Or what if you "clean" the gun with something corrosive?

Re:How Long Do They Have to be There

[Scrameustache]

if the perpetrator uses a cloth to wipe the fingerprints off the metal immediately after I'm wondering: If you wipe the metal with your hands before doing it with the cloth, would you redistribute the secretions enough to blur out any information?

Passvation layers?

[gboss]

What about metals with passivation layers, such as aluminum, titanium, and stainless steel? TFA does not address this at all... Sure, brass may be the main metal that they are going to need for shell casings, but a lot of guns are made with stainless steel.

Re:Passvation layers?

[NormalVisual]

And of those guns that aren't made with stainless, they're usually blued, Parkerized, Tennifered, etc. so your question is more than just a minor nit-pick. The finish on practically every gun made is designed specifically to resist corrosion.

Re:Passvation layers?

[Anonymous Coward]

id never heard of passivation layers before today....

Oh right..

[Anonymous Coward]

Mr. Bond!

In the gun store...

[Anonymous Coward]

Then I'll have the Magnum and a plastic skin... well... maybe that pink one with the nice flowers...

Fingerprint readers

[Anonymous Coward]

So fingerprint readers are still less secure than they used to be. Any good non-marketing reason to have them built in every high end notebook?

wear gloves

[roman_mir]

I wonder how sweaty one should be, for how long the finger should be on the surface of a bullet for it to leave such a corrosive mark, and also whether this applies to other metals, such as stainless steel?

In any case, wear gloves even while putting bullets into your guns ;)

Re:wear gloves

[Anonymous Coward]

In any case, wear gloves even while putting bullets into your guns ;)

Thanks, Already do.

Re:wear gloves

[nurb432]

Blah, lost post the first time i tried this.. anyone else have problems with safari blowing up on trying to post?

Be sure to wear you gloves when building bombs too, and use a "clean box" so you don't leave any DNA behind.

As far as bullets, if you only touch the cartridge, you wouldn't be leaving any prints on the bullet.. You are taking your cartridges with you and not leaving them at the crime scene, right?

Re:wear gloves

[NormalVisual]

And even if you do leave prints on the bullet, they're not going to be too useful once the bullet expands, even if you're using fully-jacketed rounds for some ridiculous reason.

Seeing the wood for the trees

[Hognoxious]

If the fingerprints are that persistent, then lots of other marks are going to be there too - probably including lots of other fingerprints. The hard part's not going to be detecting the prints, but separating the relevant ones out from the rest of the item's history.

Archaeology Applications

[xdancergirlx]

Does this mean that we can see the fingerprints of people that handled old metal objects/chalices/swords/etc.? Maybe it would just be an item of curiousity to have a copy of Julius Ceasar's or Queen Elizabeth's fingerprints but I would put it on my wall! Maybe we could learn something about how fingerprints have changed (or not) over the course of history.

Re:Archaeology Applications

[nurb432]

In theory, ya.

Re:Archaeology Applications

[DMUTPeregrine]

Less likely with swords though. No good swordsman ever touches their blade, only the handle, and that is wrapped, most often in leather. This is because fingerprints will corrode the metal. Swords aren't made of stainless steel, they rust quite easily. Normal sword care involves re-polishing the blade regularly, which should remove fingerprint corrosion if present. Chalices are another story, of course.

Re:Archaeology Applications

[jschen]

...if no one else touches the item!

Re:Archaeology Applications

[RealGrouchy]

Can this process be done without damaging the object, though? I don't think many archaeologists would want to risk the destruction of an artefact simply because there *might* be a fingerprint on it which *might* have belonged to so-and-so.

- RG>

Excuse me...

[ROMRIX]

I have to go smelt something real quick...

Re:Excuse me...

[sponglish]

Ladies and gentlemen of the jury:

The one who smelt it, dealt it!

Or salted lemon wet naps

[spineboy]

I mean come on - not too hard to get around, but still it's interesting.

corrosion? how much?

[Luke_22]

Great method, ok, but i dubt it works for everyone.

ok, we all have some corrosive sweat or alike in our skin, but that doesn't mean we all drop out the same amount of corrosive liquid.

there are people who can not touch a motherboard 'cause it would end with a big mark on the metal, it could even lead to malfunction, this is well known in the industry... I guess they borrowed their idea from here...

but how much of this corrosive is required for this method to work?
also, saying "metal" is saying all and nothing... there are metals that corrode easily, others that don't...

Re:corrosion? how much?

[Anonymous Coward]

Yea, cause then how far could you take it? Would it be corrosive enough to make metal parts (on things such as airplanes, cars, etc) that have been handled by manufacturing workers, fail?

Probably not, but it would be an interesting theory to test....

Re:corrosion? how much?

[TheRaven64]

I don't know the details of this particular technique, but I recently came across an approach to getting fingerprints from fired bullet casings developed by some guys at Swansea which relied on Van der Waals forces - the amount of contact required is very small.

Wrong game

[spineboy]

He's not playing Rock-Paper-Scissor, he's playing Bat-AcidSoakedSponge-Saw. The hand motions are a little strange though.

Re:Wrong game

[Anonymous Coward]

Cat-Tinfoil-Microwave anyone?

WTF, haven't we known this?

[IceCreamGuy]

I swear I read the same thing in "The Hardy Boy Detective Handbook" as a kid.

Re:WTF, haven't we known this?

[Llamalarity]

Nope, not in the 1959 edition. (1971 printing) Did they revise it for you whippersnappers? "The Hardy Boys Detective Handbook" does however give a very detailed explanation of the basics of fingerprinting. Which probably has not changed much since then.

Thanks for the trip down memory lane!

Re:WTF, haven't we known this?

[IceCreamGuy]

I do have the original; I could swear they mention that a fire will make fingerprints more permanent. I could be completely mistaken, though. I can't believe I missed that "s."

JFK

[Hao Wu]

Now we can prove whether Oswald killed JFK.

Re:JFK

[Scrameustache]

Now we can prove whether Oswald killed JFK. IIRC, the bullets were lost.
As was the presidents' brain.

And anyway, the files are covered up by the government for [life expectancy at the time] after the events, 2033 I think. So "now"... not so much.

SANDPAPER!

[DragonTHC]

SANDPAPER!

fail!

Corrosion is a complicated subject

[Kupfernigk]

I have actually done research into chloride corrosion of brasses, and the answer is that it is enormously variable. Whether the brass is turned or stamped, the temperature, the number of steps in the stamping process, the sharpness of turning tools, the final treatment (grind to size, polish etc.) all affect the rate of attack. One would expect much the same for other metals, though considerable research would be needed. This will probably become a nice little earner for expert witnesses.

Re:Corrosion is a complicated subject

[etully]

Can we examine pieces of metal from hundreds of years ago? Can we find out what George Washington's fingerprints looked like?

Not new

[russotto]

I'm pretty sure this is not new, or at least the basic idea isn't. In fact, I recall reading a detective story set near the start of the fingerprinting era, where an old murder case (from before fingerprints were used) was solved by the detective using a fingerprint that was actually visible in corrosion on the doorknob of the room the murder took place in, the room having been closed off since the murder.

Who has them now?

[Anonymous Coward]

This makes me wonder about the 9mm Luger that I had stolen a few years ago. Also I wonder about my buddy's Army 45 that we swapped at the firing range that he also lost!

NaCl

[Anonymous Coward]

It is an extremely expensive and time consuming procedure, but one could always subject the weapon to an NaCl bath.... Course, then, only millionaires would get away with murder.

Re:NaCl

[Arimus]

Err... expensive? buy a tub of marine salt (the kind you use to mix for marine fish tanks) and dump the weapon in that for a few weeks - ideally heated and then place in a bag and leave to corrode...

By Neruos

[Anonymous Coward]

This is FUD. Sorry but you can not get finger prints from this. The acidic chemical nature of finger prints, mainly the sweat, is not strong enough to continue to be detected after a strong cleaning. No matter what microscope or detection you use.

And if it could be(which it is not!), just clean the material in a sweat type solution to blank out everything. Remeber most prints smug and require more then 1 to make an offical match, don't believe what you see on TV.

Possible to reliable ...

[Anonymous Coward]

The route from "it is possible to" to "we can reliably do" is a long one, and filled with obstacles.

Let's see some real world operational-use results first, before getting all excited. If it reliably works as implied, it looks like a very useful tool indeed.

-srr

Digital photos can still be evidence!

[Terje Mathisen]

The requirements are pretty though though:

You need a special camera version which contains firmware (hopefully tamperproof) which uses public key crypto to digitally sign each photo as it taken, making it possible to prove that the photo file hasn't been modified at all.

One example is the Fujifilm IS Pro which can be delivered in this form:

dpreview Fuji IS Pro review

Terje

Re:Digital photos can still be evidence!

[TheLink]

In theory you should be able to get the key from the camera and use it to sign whatever photo you create.

If the feature actually works (keys/crypto not broken etc), you know that photo or tampered photo is unlikely to be created by someone without access to that key.

But if you have had access to the camera, you might have the key.

That puts me at how many crime scenes?

[Kasis]

When I left school I had a job in a metalwork factory, and our area of business was the hand driers you find in public toilets. We made several types with metal covers, and during my time there I probably handled thousands of the things.

I wonder how often my fingerprints will appear at crime scenes now?

Re:That puts me at how many crime scenes?

[wronskyMan]

Probably as often as all the other millions of people that touch driers in public restrooms.

Re:That puts me at how many crime scenes?

[Kasis]

My point exactly...

So who's going to follow up all these millions of leads?

Problem solved for criminals:

[HairyNevus]

Steel wool/a file would abrade the metal, ruining the fingerprint.

Re:Problem solved for criminals:

[srmalloy]

If you're going to police the area for your spent brass after you shoot someone, you're better off using a revolver, which won't toss empty cartridges all over the place. Beyond that, if you're doing it someplace where you don't already have your prints all over the place, thin gloves will keep you from leaving fingerprints in the first place... and you can dispose of the spent brass and gloves in widely-scattered places unrelated to the crime. If you're near the ocean, toss them in; the effect of the ions in the salt water will make any residual markings on the brass unrecoverable fairly quickly.

try recovering fingerprints from dusty items

[momotarosan]

a detective once told me that it is hard to recover fingerprint on many objects found outdoors. dust tends to settle on outdoor objects, and often you won't find any fingerprints if the object was dusty. Also you tend not to leave a fingerprint on very rough objects such as a brick.

CSI

[Anonymous Coward]

(Overly dramatic voice): The suspect might be smart enough to wipe his fingerprints off the gun but the corrosive sweat never lies.
(Puts on sunglasses)
Cue The Who... Yeaaaaahhh!

wow@

[Anonymous Coward]

good to know that the horrible people who commit hanous crimes have one less way of getting away with it, seems like now wipping away stuff on some guns will be a thing of the past, unless they are smart enough to wear gloves. It's good to hear that science is catching up to these criminals

Quincy did this already

[Anonymous Coward]

If you were as old as I, you might remember that Quincy (Jack Klugman) claimed to be able to do this, faliciously, to a murder suspect, in order to trap him a few scenes later. That was in the late 70s.

I always thought it was good techno-babble and only a matter of time.

All you need to kill is sweat a little now!

[flayzernax]

Corrosion is caused by chloride ions from the salt in sweat.

So do a good work out and wipe your gun down with your sweat...

Metal gets all corroded and no one knows wtf was holding on to it other then a sweaty 40 yr old Italian mafioso.

Today's lesson...

[marciot]

Remember kids, wipe down your murder weapon with sand paper!

Simple solution

[PPH]

Pick up your brass.

meh

[ramul]

so can we use a spray bottle with saline solution to clear tracks?

More forensic 'science' vaporware

[exp(pi*sqrt(163))]

As everyone should know by now, real life is not like CSI. Forensic science isn't the science of discovering who committed crimes, it's the science of making up the most believable science fiction to convince people not to commit crimes, and making up the most plausible BS to bamboozle juries in court. Claims by forensic scientists are generally judged by highly idealised lab situations that bear little relation to real crime scenes. And the scary thing is that when papers are published judging the efficacy of such methods, the papers repeatedly use circular reasoning where correlations between positives from technique X are correlated with event Y even though X was used as evidence in court when determining whether or not Y took place, so they'd appear correlated even if X and Y were competely unrelated. Forensic science ranks up there with cold fusion for pseudo-science. Actually, I think I have more faith in cold fusion.

Re:More forensic 'science' vaporware

[lpangelrob]

As my lawyer friend says... the court of law doesn't necessarily judge based on who actually did the crime. It judges on who has the better story.

That said, the story still has to be based on a fact.

But who's going to pay for it?

[newgalactic]

This and all CSI type investigative technics should be taken as scary in theory, but non-threatening in reality. Why? Because they're expensive. You can rest assured that only the most serious crimes will warrant this type of expenditure. For goodness sake's, our US bridges are falling apart, and those are used everyday. If we can't afford that, you can rest assured that money will also be tight when investigating criminal activity.

So... fingerprints are even recoverable from...

[thrill12]

money...pennies ?

Sorry, pun intended ;=)

seriously?

[Anonymous Coward]

*sigh*

*leaves country*

Loading != pulling the trigger

[Muad'Dave]

"As you are pushing the magazine in you are actually putting a thumb print on the bullet," said Bond. "That's the person you want. That's the guy who loaded the gun."

Wow! Just loading a firearm is prima facie evidence of murder!

So if someone steals my loaded pistol, or even a pistol and ammo I've handled, I'm guilty of murder. Nice.

What sci-fi imagines is now real?!?

[Darth_Keryx]

Dan Simmons in his monumental _Hyperion_ series, specifically book #3 _The Rise of Endymion_ writes about how the Pax authorities on Mare Infinitus are able to lift Raul Endymion's fingerprints from a coffee cup that has been washed multiple times "using the latest forensic techniques". (They did not realize of course whose fingerprints they were - at the time he was some unidentified fellow who showed up and got into trouble with the local authorities.) I remember thinking "you gotta be kidding - no way you can do that". And here we are talking about... lifting fingerprints from something that has been washed multiple times. Once again what science-fiction imagines in the far distant future is being developed even as we turn the page.