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Computers, Court, and Fingerprints
Degrees writes "Should Law Enforcement be allowed to Photoshop fingerprints? That is the question posed in this article in the South Florida Sun-Sentinel. The suspect is charged with murder, and the evidence was circumstantial before the fingerprint enhancment. At the end, the crime scene investigators say they want encrypted cameras. The implication is they want DRM-enabled digital cameras with software for full audit-trail capability. Would that make the Photoshoping more credible? Would DRM cameras be a good thing for Joe Citizen?"
I could to that!! Get a print of my enemy, photoshop it and presto, we've got a conviction! Do the judges have any idea what can be done with Photoshop in the hands of someone who has used it before?
At least the war on the environment is going well
DRM is about taking options away from users. This is about providing users with a new option: a strong audit trail. You can make a copy of the image using non-auditing software, but that copy of the image would lose it's "seal of approval." The original would remain valid. The end result: cops can make any copies and image manipulations they want that may help them solve a case. But in court they'll only be able to present images with the valid audit trail, ensuring that the image was never mishandled and clearly showing what manipulations were done to it. It sounds like a great idea and I strongly support this option for users. (I am suspicious that it may not be possible... but I'm happy to let people try.)
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Note that this is "trusted computing" in service of the owner of the computer (in this case the police department and department of justice rather than the individual operator). The fundamental difference is that the owner of the computer is the one asking for the trusted service, rather than some other entity that does not trust the owner of the computer.
Bruce
Bruce Perens.
I don't think that the question is whether this should be legal. The question is if evidence gathered in this way should be admissable in court. While this isn't the same as the cops taking evidence from your house without a warrent, you do have to worry about the accuracy of the technique and whether it should be allowed in court. They mention in the article about going in and digitally removing "interference" like weaves of fibre. Who is to say that the removal technique is good enough to recover the fingerprint exactly? What if the removal process adds/subtracts features from the fingerprint itself to the point that it appears to be a match but might not be?
It seems to be a useful technique for gathering evidence to find a suspect, but I'm not sure that I'd want it to be key evidence for a conviction.
That's funny, I posted a link to the appropriate info yesterday, here it is again
Here is a good article that covers a lot of this
The "Authenticity Crisis" In Real Evidence
Scientific Evidence Review
10.1.2001
You might also be interested in the KODAK Picture Authentication Module [kodak.com] which uses PKI in a camera.
If I post before the story goes up is that a "Zero Post "?
Having been involved in traditional analogue photography for 30 years, I can tell you that I'd trust one of those Kodak cameras more that say a 35 mm Ektachrome Transparency, or worse yet, a color print. A while back Polaroid was blowing out a digital printer that output on spectra film for 30 bucks. I considered buying it for all sort of practical jokes and parking ticket disputes.
I use to deal with a company in UK who handled remore control and transmission of real time video from security cameras and similar.
They told me that digital material is only treated as 'evidential' by UK courts if it has not been processed digitally any way. Raw data from digital cameras is ok, but lossless compression (zip, rar etc) cannot be used before storage or transmission of data. Thus encryption is not allowed, and lossy processing like MPEG? Forget it.
This is one reason why security recording are still largely analog - VCRs. Another reason is that VCR tapes are cheap, hold a hell of a lot of information, don't take up much room, and can be re-used.
It is probably fairly easy to present reasonable doubt of digitized evidence unless the resolution is so that tampering would be detectable.
Hmm, you can't really use it to get leads either. Any evidence that comes from inadmissable evidence is inadmissable itself.
For example, say I illegally search a house. I find a note, the note has the name of someone involved in the crime I'm investigating. I go find the guy with that name, he confesses.
His confession, the fact we know him, and the note itself are all inadmissable because it was the fruit of an illegal search. However, we're human, the court can't erase that from memory. So we know 'who' did it, but now we have to go link them another way. That of course is a simple example and not legal fact. Thats why they pay lawyers tons of money.
..There's a-dooin's a-transpirin'
Hmm, you can't really use it to get leads either. Any evidence that comes from inadmissable evidence is inadmissable itself.
I believe that you're wrong.
If you're given an anonymous tip, or someone takes a lie dectector test, you can't use these as evidence--but you CAN use them to get evidence.
Anything that comes from ILLEGAL police procedure is tainted. Not just inadmissable evidence.
Well, that depends. The customized filter could be rigged to only enhance certain traits that are known to be part of, but NOT EXCLUSIVE TO, say, fingerprint ridges. So you run the image thru the filter and suddenly, because the existing data fell into the trigger range, pixels get enhanced that shouldn't have been.
Having amused myself by mixing filters and data in all sorts of weird ways, I can tell you that often the results are not simply enhancement. Data disappears, artifacts appear, either of which could create spurious fingerprint ridges. So aside from the possibility of simple pixel painting, it is open to abuse.
I don't think the principle is bad, but rigorous standards would have to be developed and applied, including a complete audit trail (and incremental files) for each image.
~REZ~ #43301. Who'd fake being me anyway?
How would you code something to prevent tampering? Admittedly, I'm a dumb-assed cop and no programmer, but I don't know how I could even define "tampering" in language that a compiler could understand.
Police already have legal requirements for speedo calibration in cruisers, and other standardization requirements.
Relatively few. Our policy (one city in Colorado-YMMV) on speedo calibration is to just let the factory do it. (On the Crown Victoria, the factory calibration is good forever so long as either the original tires stay on the car, or the replacements are the exact same size.)
Training requirements are theoretically standardized by state POST boards, but there's a LOT of variability there.
And about the only Federal standard we have (other than what the courts set) is the standards we meet in order to have NCIC access.
I would support police digital enhancement, just as long as it was strictly monitored and reproducible: that is, a secure source image must be used and provided so opposing technical experts could reproduce any enhancement when provided the methodology by prosecutors.
That's not that different from how we do it now. Any time I bring a photo into evidence, you can damn well bet that I can produce the negative for inspection/comparison on demand. Any image manipulation or enhancement needed, I can explain and walk the court through what I did and why I did it.
Unfortunately, without a negative, ultimately I'd have to ask the judge/jury to take my word for it. Our justice system is based on the fact that they're not supposed to do that. They're allowed to use their common sense (well, maybe he COULD have altered the negative with the super-secret machine brought down by the flying saucer aliens, but...) but they're also supposed to understand that "trust me" is just a polite way to say "fuck you."
It's that whole thing about an unaltered and unalterable negative which actually makes photography credible in court. Without it, we have a much harder time making our photos stick. I can start by testifying that the photo accurately represents the scene as I found it, but as long as there are people in this world with the ungodly stupidity to take Alan Dershowitz at face value, I have to plan on needing more than that.