3D Fingerprinting — Touchless, More Accurate, and Faster

kkleiner writes "For all the glory it gets, the fingerprint has evolved very little in the last 60 years. They’re still two dimensional. The US Department of Homeland Security and the National Institute of Justice are hoping to change that. They've given grants to dozens of companies to perfect touchless 3D fingerprinting. Two universities (University of Kentucky and Carnegie Mellon) and their two respective start-up companies (Flashscan 3D and TBS Holdings) have succeeded. Fingerprints have reached the third dimension and they are faster, more accurate, and touchless."

Comments

fingerprinting

[nomadic]

There is probably no scientific evidence relied upon unquestionably, that has such serious issues regarding accuracy as fingerprinting. Check this out.

Re:fingerprinting

[Hatta]

Yep, here's more from Boston University

A more fundamental problem is the lack of underlying statistical evidence. The use of genetic evidence provides a good comparison. Scientists and lawyers subjected the technique, developed in 1984 and first introduced into a U.S. court in 1987, to years of scientific scrutiny and almost a decade of court challenges before it became accepted evidence. In DNA analysis, examiners identify and compare short segments of DNA--generally 13--to make a match. In addition to having established procedures for analyzing evidence, experts have calculated the odds that two people could share the same DNA in all 13 segments. These odds vary slightly based on the prevalence of certain DNA patterns among different ethnic groups but are in the tens of millions to one against two people sharing all 13 segments.

Fingerprint examiners frequently tout the permanance and uniqueness of fingerprints, but they do not know the odds that two people could share a given number of fingerprint characteristic. With no clear rules for how much relevant weight to give to the various print characteristics, like point matches, ridge width, and the spacing of oil pores, German argues that it is impossible to attach probabilities to print identifications. Many experts believe probabilities are unnecessary since examiners would not make or confirm an identification unless they were certain of it. But when three of the most experienced FBI examiners confirm a mistake, as they did with Mayfield's prints, the argument collapses. Other print proponents argue that despite occasional human errors, the method is infallible. Critics like Simon Cole, a legal historian who has testified in many of the court challenges, rightly point out that this is a useless distinction--for whatever reason, fingerprint identifications are sometimes wrong.

The handful of studies of fingerprints show a troubling pattern of errors. Since 1995, Collaborative Testing Services, a company that evaluates the reliability and performance of fingerprint labs, has administered an annual and voluntary test. It sends fingerprint labs a test that includes eight to twelve pairs of prints that examiners confirm or reject as matches. The pairs usually consist of complete, not partial prints, making identifications easier than the real situations examiners face. Nevertheless the error rate has varied from 3% to a dismal 20%.

Fingerprinting has never been scientifically valid

[spun]

I came here to either find or make this comment. Good job. Police and prosecutors build their careers on convictions. They have a vested interest in the public believing in the infallibility of fingerprinting. I find this paragraph from the New Scientist article to be key in understanding the controversy of fingerprinting:

No one disputes that fingerprinting is a valuable and generally reliable police tool, but despite more than a century of use, fingerprinting has never been scientifically validated. This is significant because of the criteria governing the admission of scientific evidence in the US courts.

Re:Great! Now I can be fingerprinted passively!

[just fiddling around]

Did you take an international flight into or out of the US lately? If so, you are in the database with all the "bad people".

As for computational intensity, CPU cycles are cheaper than dirt, and getting even cheaper than that by the minute.

Re:Cost

[KillerBob]

When talking about convictions, yes. False positives are worse. When talking about investigations, false negatives are worse. A false positive during an investigation means that you spend a little time and resources investigating and proving somebody's innocense. A false negative during an investigation means that you might let the guilty party walk free, uninvestigated, because you don't believe they're the one.

In an ideal world, at least. :) In the real world, things are never so cut/dry as that.

Re:Great! Now I can be fingerprinted passively!

[HiThere]

What's the rate of false positives? If you say there aren't any, I'll know you're lying.

The correct answer is "Nobody knows, and the research to calculate it isn't allowed."

For normal finger prints this could have been calculated decades ago, but the necessary agencies have consistently refused to permit their techniques to be evaluated. (Others have said that informal estimates show up to a 20% error rate [varies with the lab and the time period...low estimate was 3%]. I think was was being investigated was false negatives, though. I don't know the study, so I can't say for sure. This was reported to be based on voluntary cooperation of the fingerprinting labs, though, so the real numbers are probably higher.)

(OTOH, the study reports may be someone's invention. I haven't seen it. I do know that there had been no official evaluation the last time I looked into the matter [a few years ago].)