Is Latent Print Evidence Infallible

[Big Wullie]

Having read the following article I have serious concerns that far too many mistakes are being made with the end result being far too many innocent people are in our prisons:

Are they infallible and why ?

Study: Fingerprint Evidence Isn't Infallible
Researcher Says Faulty Analysis Can Occur and Is Difficult to Detect

A single fingerprint found at the scene of a crime is such powerful evidence that it's almost an automatic conviction. Fingerprints never lie: Juries have been told that for more than a century.
But a criminologist at the University of California, Irvine, has documented 22 cases most involving violent crimes, in which fingerprint evidence turned out to be dead wrong, usually discovered after defendants had served time for crimes they did not commit.
The fingerprints didn't lie. But the experts who matched them with a suspect were wrong and subsequently had to admit it, according to court records analyzed by Simon Cole, assistant professor of criminology, law and society at Irvine.
Cole's exhaustive research argues that the "zero error rate" claimed by fingerprint experts needs serious retooling. His findings are published in the current issue of the Journal of Criminal Law & Criminology.
'A Miscarriage of Justice'
The cases include one man who volunteered for hazardous assignments while in prison to earn money to pay for DNA research involving his case. That research eventually cleared him, despite the fact that experts had testified that his fingerprint implicated him in the attempted murder of a police officer.
In another case, a corpse found in the Nevada desert was identified – on the basis of fingerprints – as that of a California woman who later turned up alive.
Most of the cases studied by Cole were covered by the media, partly because they involved sensational events like the Madrid train bombing last year that killed 191 people. Cole suspects there are many other cases, possibly more than 1,000 each year in the United States alone, in which fingerprints have been matched erroneously with the wrong person.
Cole isn't saying that fingerprints are not a useful tool for law enforcement. All he's saying is their "error rate" is more than zero, and some way needs to be found to put their reliability into perspective.
To tell the jury that it's positive identification, that it's infallible, that it's 100 percent certain is overstating the value of it," Cole said in an interview. "It may well be that it's right 95 percent of the time, but when it's wrong it's very unlikely for us to know about it. So it's likely to result in a miscarriage of justice."

There are multi-layered programs designed to prevent errors, including a requirement for independent verification. Cole found only 22 cases, spanning several decades, but he was limited to cases that have come to public attention.
"An analysis of these cases shows that they are most likely only the tip of the proverbial iceberg of actual cases of fingerprint misattribution," he writes.
In most of the cases he studied, the error did not surface during the routine processing of the case. It surfaced because of "extraordinary circumstances," such as the confession of someone else, which Cole describes as "always a fortuitous and highly unlikely event." So he concludes there are probably many less "fortuitous" cases where the error is never discovered.
Perfect Method, Imperfect Analysts
Part of the problem stems from the nature of the evidence itself. Fingerprints taken from the scene of a crime (called latent prints) are not always clearly defined.
"They are typically partial, smudged or otherwise distorted," according to Cole.
That would seem a clear path for errors, but experts routinely testify that the "methodological error rate" is zero. How can that be, especially now that several cases have surfaced?
When fingerprint analysts testify that the method is perfect, they are talking about the fact that no two fingerprints are exactly the same, so one and only one person can match the prints. They frequently use mathematics as an analogy.
The equation 2+2=4 is correct. If a mathematician comes up with an answer of five, the method isn't wrong – the mathematician is.
But the chance that the fingerprint analyst is wrong is not taken into account when the evidence is presented to the court, Cole says. Repeatedly, during the 22 cases he documents, the experts testified that the chance of error was essentially zero.

Madrid Mix-up

The most celebrated case of mismatching involved a Portland, Ore., lawyer, Brandon Mayfield, who was arrested and held for two weeks as a suspect in the Madrid train bombing last year.
Spanish National Police sent fingerprints from the crime scene to law enforcement agencies around the world, including the FBI, in an attempt to identify the bomber.
Mayfield, in retrospect, may have been a sitting duck. He was a Muslim convert with an Egyptian wife, a United States Army veteran, and he had once represented one of the "Portland Seven" who had pled guilty to conspiracy to wage war against the U.S.
Spanish authorities questioned the match, and the FBI even sent agents to Spain to try to convince them that Mayfield was their man.
Spanish police, however, found another man who was a better match for the prints, and Mayfield was released. At the time of his arrest, Mayfield told authorities he had not been out of the country in 10 years, and didn't even have a passport.
And according to Cole, one of the FBI agents who had insisted the fingerprints were those of Mayfield had been reprimanded for making false attributions in 1969 and 1974.
Exonerated by DNA
One of the most troubling cases involves Stephan Cowans, who was convicted of attempted murder in 1997 for allegedly shooting a police officer while fleeing a robbery in Roxbury, Mass. He was implicated in the crime by the testimony of two witnesses, including the victim, and a fingerprint found on a cup.Cowans insisted he was innocent, but several experts testified that the fingerprint was his. He was convicted and sent to prison.
While in jail he volunteered for "biohazard" work assignments to earn money for DNA tests. Three DNA samples from the mug and from a hat and a sweatshirt discarded by the perpetrator all excluded Cowans.
As a result, the Boston police department re-examined the fingerprint and determined that the match had been an error. It was later found that one of the fingerprint experts who had testified at Cowans' trial had "discovered" the error but concealed it.
Cowans was released, but he served six years in prison for a crime he did not commit.
And he owes his freedom not only to his own perseverance, but to happenstance as well. If the real villain had not been "so obliging" to drink from the cup and discard two pieces of clothing containing his DNA, "it is virtually certain that Cowans would have served his full sentence of 35 years without anyone ever knowing that the fingerprint evidence (and the eyewitness evidence) was erroneous," Cole writes.
It doesn't exactly sound infallible.
Lee Dye's column appears weekly on ABCNEWS.com. A former science writer for the Los Angeles Times, he now lives in Juneau, Alaska.

[David Johnson]

Of course fingerprint evidence is not infallible. It is is very very good and in most cases it is very reliable evidence but it is done by human examiners and so there is a possibility however small of a mistake.

The "criminologist" that I think you are referring to is Simon Cole, and he is not a fingerprint examiner and is just a vocal critic.

The case in Nevada was a finger print exam that was done by someone who was not a latent print examiner and they should not have been comparing the prints.
In his research if he was only able to come up with 22 examples were someone had gotten it wrong either because of ethics or lack of training I dont think that paints a dire picture for the rest of the community.
And when errors have been discovered they have found that the error was not caused by the two people having identical fingerprints but instead that the examiners in the case had made a mistake.
We may not know the exact error rate for fingerprint identification but it is rather small and even if it is not infallible it is highly reliable evidence.

[Gerald Clough]

Big W,

While most who post here are quite familiar with Cole's work, it's always good to see how non-examiners reflect on it. So, a few responses:

Cole has no experience as a latent print examiner. This doesn't mean he is not allowed to comment or to study some of the issues. But keep in mind that he has made quite a good thing of playing the critic.

He is one of the "it's not science" critics. From an academic or pure science view, the conclusions of latent print examiners are absolute and presented as final and not open to revision. That's pretty powerful stuff to a scientist whose orientation is that in almost all inquiries, the conclusions are understood to be merely a step in an endless chain of discovery and always open to revision. In the sciences, if one were to claim one's conclusions as the be-all and end-all of that line of inquiry, your peers would require the most extraordinary proofs, and many would not accept any proof as that powerful, if for no other reason than the guiding principles of scientific research. In other words, the conclusions of fingerprint identification grate on the scientist, for the imagined required proofs are not there. Their error is mistaking the purposes of the two kinds of inquiry. The forensic comparative disciplines (indeed, all fields that contribute to legal evidence) are conducted to provide those who try legal issues to one or another standard of persuasion with useful information. Any information that was a generally accepted bit of scientific knowledge would not be a reasonable issue to be heard. It would be simply a recognized fact, known to the court or available from anyone in the applicable field, and any expert would do, since all would agree. One does not need a contest of experts in court to decide if the moon was full on a given night. A standard reference or a single astronomer would suffice. But the issues in legal contests involve other analysis that can be valuable and even essential in the process of deciding the greater issue, and those analysis cannot be excluded merely because they are not universal scientific fact or even that experts will disagree. (Frank disagreement between experts is far more common in some other forensic fields. In some, it is expected and nearly inevitable. Nevertheless, these fields are essential to deciding some of the most grave issues of literal life and death.)

I fear, though, that Cole falls into violating the scientific rigor he desires in his efforts to support what he believes to be valid objections. He guesses at 1,000 erroneous identifications. He accepts that estimate but provides nothing resembling scientific evidence for it. Rather, his evidence for that number is objectively weaker than the latent print examiners' belief that 100+ years of close observation supports his methods. Further, he conveniently ignores the meaning of "exoneration." Legal exoneration does not equate to proof of innocence. In many cases in which DNA analysis has been a factor in reversing a conviction, the DNA results do not prove anything but that someone other than the accused contributed some bodily material to the scene and that the accused did not or that the accused's was not found. In some cases, the nature of the material from which DNA is drawn and the place it is found do indeed at least show another likely actor. In others, it merely presents evidence that, if known at the time, might have prevented conviction and may be so situated that it makes conviction at retrial too unlikely to attempt. This is a common misrepresentation among many who comment on the criminal justice system. These case can only have any meaning in a discussion of the reliability of fingerprint evidence when the actual fingerprint evidence itself is examined. And that decision must often be made, not on the basis of rationally balanced proof, but on the habits of juries.

Cole also misrepresents the latent print examination discipline's claim that the analysis is infallible. I think it is a willful misinterpretation, since he does know the difference, but I think it grows out of his misguided and fantastical desire that nothing not "scientific" be presented as fact. He correctly reports that fingerprint experts cannot describe this infallible process in terms that would be accepted as the methodology of a pure scientific experiment. But he misses the point that in all fields of forensic expertise, experts testify to their conclusions using methods that they consider will always produce correct results when properly applied. It is the very nature of the admission of expert conclusion to legal inquiries that they may be contested by other experts.

Cole's alarmed response to what he sees as the fallibility of fingerprint identification is misplaced. He may be justifiably alarmed that fingerprint evidence is very often unchallenged, even unexamined on behalf of the defendants. He may be alarmed that much of the reason is historical, not analytical. But it is fantastical to expect a forensic discipline to spontaneously provide adversarial advocacy. That is absolutely the responsibility of the court and its officer, the attorney defending. I agree that it's is not often enough provided. But that is in no way a failing of the fingerprint discipline. It is, perhaps, understandable that the attorneys do not demand it in every case. The accuracy of the examiner's conclusion is almost always evident, even to a non-expert attorney. Nevertheless, it should be more available. He should he hectoring the courts, not the examiners, but his appearances in court are attempts to attack fingerprints, not the omissions of the court. And he is consistently rejected as an expert, largely, I think, because the courts simply recognize his mistaken focus. In words that might be more legally oriented, he has nothing to offer as an expert to assist the triers of fact, even though he might, if presented that way, offer advice to the court on the issue of providing defense resources. He would, I suppose, be disappointed if the court did provide an adversarial expert, since they would also be applying that he sees as flawed science.

[L.J.Steele]

In his research if he was only able to come up with 22 examples were someone had gotten it wrong either because of ethics or lack of training I dont think that paints a dire picture for the rest of the community.

Are you really claiming that the Mayfield error was a training or ethics issue? How about Roger Caldwell? Riky Jackson?

See
http://www.clpex.com/Articles/Newz/2002 ... 2-26-3.htm

I'll grant you that the Cowans error is less clear, in part because, as far as I known, BPD has still not make the underlying latent and court exhibits publically available.

The problem, as Cole has pointed out in various articles, is that by its nature print errors are hard to uncover. The defendant needs to decide to fight the case. He or she needs to convince a likely skeptical defense attorney to have a well-trained examiner look at the print evidence with a skeptical eye (and avoid the confirmation bias issue that caused the court-appointed examiner to miss the Mayfield error). If the client is broke, appointed counsel may need to convince a skeptical supervisor or judge to grant funds for said expert. The expert has to find the mistake. Assuming at that point, the state's expert, confronted by the contrary opinion, doesn't ceded the point, then the defendant has to be willing to roll the dice and take the case to trial and win. And even then, two differing opinions may not be accepted as proof of a mistake -- just look at the debates here about "the Scottish print".

Alternately, the defendant needs to be lucky enough to have airtight evidence showing that he can't be the culprit -- and have that evidence preserved, properly tested, and tested by someone blind to print result to avoid confirmation bias on their part.

By its nature, errors are going to be hard to find. If Cole is suggesting say, 1,000 a year -- that's a very tiny amount when one considers the hundreds of thousands or perhaps millions of print examinations done each year in the U.S.

I think the take-away lesson remains don't get overconfident. Mistakes, like black swans, happen.

[Big Wullie]

How many experts have ever changed their minds once in court giving evidence ?

How many experts have ever admitted in court Fingerprint evidence is not infallible ?

We all know there have been many many mistakes and wrongly accused sent to prison but How many experts have ever admitted in court they were wrong. ?

How many experts have ever said in court their evidence was not 100% concrete evidence ?

Does anyone think Juries deliberations would be different had they been told Latent Print Evidence is not infallible ?

How much influence does one think their evidence plays a key role in convictions ?

I know in Scotland the talk on the streets is: no-one would trust fingerprint evidence in our courts after the Shirley McKie and David Asbury cases, Don't know about America or other Countries.

[Michele]

Lisa,

I know we've had this conversation before, and we both have different opinions about the value of blind verification, but this time your own example proves my point that a lack of information doesn't lead to better conclusions.

You suggest that someone needs to look at a comparison blindly in order to find errors. Researchers have shown that bias is only a problem when the latent print is ambiguous, when the quality and quantity is marginal. This involves a very small percentage of the latent comparisons that are done.

Do you know of any errors that were found only after someone looked at the comparison blindly? Blind verification may show that a conclusion isn’t easily reproducible but I don’t know of one case where blind verification found an error or confirmed an error. Limiting information may prevent bias but it also limits a person from arriving at a good conclusion.

You brought up a perfect example, the Caldwell case. In this case the examiners you spoke of had very little knowledge about the previous examiners conclusions. Contrary to the article you posted, they didn’t not testify that “the prints didn’t match”. They looked at the film negatives and determined that (I don’t know the exact wording) “nobody could make an ID with these images”, (because the images were blurry) and therefore it was determined the ID’s must have been erroneous.

If someone would have looked at more information (instead of limiting the information) they would have known that the original examiners didn’t do there comparisons against the blurry negatives, they did their comparisons against the actual evidence. Caldwell’s original witness knew this and that’s why he confirmed the ID, but when the new trial came about with new examiners who lacked the original information (by now the original prints had faded) then they made too many assumptions and came to a poor conclusion that the comparisons were erroneous. Your own example shows that limiting information doesn’t make people arrive at better conclusions!! Unfortunately the critics only want to look at information that supports their views so they ignore the correct information. I’ve seen interviews with Caldwell’s attorney and he said that he knew the truth but he wasn’t trying to get to the truth, he was trying to get his client found innocent, which he did.

An interesting side note is that just a few years ago, DNA was tested on this evidence and it was identified as Caldwell’s. This goes to show that when there’s a lack of information then people tend to fill in the blanks with information that they think makes sense but it’s often wrong. Blind testing has its place but not as a way to check if conclusions are valid or not (it should be used to check for reproducibility). Good science recommends collecting as much information as possible, in most cases it doesn’t recommend limiting information.

[Michele]

A good friend of mine told me that my post should probably be clarified (thank you).

In the original trial, the examiners used the original evidence (an envelope) to make the comparisons. I can see this happening. I know of a lot of offices that used to take pictures of latents on paper but while they were waiting for the film to be developed they’d make the comparisons to the actual evidence. The verification would also be on the original evidence. Once the film was developed then it was filed in the case and never checked to see that the pictures were in focus.

During the second trial, the prints had faded on the envelope but that might not have mattered because the only evidence the defense experts were given was the film negatives and the ten-print card. They concluded that the film negatives were too poor to make an identification. I've always wondered why they didn't re-ninhydrin the envelope but I guess nobody thought of it or they just weren’t asked to do so.

My point in the Caldwell case was that people may need more than what they are given. If people are expected to analyze a situation then they need all the data possible because we don't know what data is important and what data isn't important until we are given that information to study. Limiting information (blind verification) doesn't lead to better conclusions.

People are way too willing to have faith in blind verification because the FBI has implemented it, it’s in the SWGFAST documents, and academics are recommending it. Blind testing does have some value but it shouldn't be the 'end all, be all' way to determine if a conclusion is correct. It shouldn’t be used to ‘check’ a conclusion because how someone arrived at a conclusion isn’t being checked at all. People need to consider all the information in a case and not limit the information because they are afraid that bias will creep in. There are other ways besides blind verification to check for bias.

Here’s an example of blind verification. Suppose you are given some data and you’re told it’s a blind verification. You take what you are given and arrive at an independent conclusion, but is this an independent conclusion of the same data? What if you weren’t given the same data the original examiners were? Maybe you were given film negatives or photographs, we know reproductions could be degraded and that could effect the conclusion (as it did in the Caldwell case). How can you claim this is an independent conclusion of the same data….it may not be the same data at all. Limiting information may not be checking the previous conclusion and it may not be arriving at a better conclusion. It could be an independent conclusion of different data. IF an agency is going to implement blind verification, I think they need good procedures in place to insure that the verification is only restricting irrelevant data and not restricting relevant data.

Blind verification can be a good tool but only if it’s used correctly.

[L.J.Steele]

You suggest that someone needs to look at a comparison blindly in order to find errors. Researchers have shown that bias is only a problem when the latent print is ambiguous, when the quality and quantity is marginal. This involves a very small percentage of the latent comparisons that are done.

Actually, I think I've agreed several times on this forum that confirmation bias seems to be primarily a problem when the data is ambiguous. The problem, of course, is defining what cases are the ambiguous ones and which are the obvious ones. I hadn't brought that the question of when a crime lab might want to blind-test in this thread as I was just dealing with the question of why it dangerous to rely on the absence of known mis-IDs to conclude that there aren't very many. (What's that phrase about absence of evidence and evidence of absence....)

A defense expert review, by its nature, isn't going to be blind. The expert is being hired specifically because someone else has reached a conclusion inculpating the defendant. Likey, a defense expert is only going to be hired if the print evidence is the key, or only, inclupating evidence in the case or if the client has beaucoup money to check everything. And likely, if the defense attorney looks at the match and says "Dang, that's obvious", then he or she is going to pressure the client to plead and may not bother hiring the expert. That's not to say the attorney is right -- but there just isn't enough money in the indigent defense budgets to retest everything. I'd suspect that the body of cases the defense expert sees will tend more towards the ambiguous cases than towards the more routine lab work.

Thanks for the extra details on Caldwell. I hadn't seen that information. The point about Mayfield, and likely Jackson, still stand tho -- those don't seem to be either training or ethics failures -- they were mistakes that could probably happen to anyone. All I'm suggesting is that one ought not get overconfident.

[kevin]

Its hard to keep reading after you see Simon Cole's name in there...