The Myth of the Fingerprints: Is Fingerprint Analysis Science Another Discredited and Untested Forensic Technique?

Share:
Fingerprint-AnalysisYesterday the Yolo County trial of Oscar Barrientos opened.  Mr. Barrientos is accused of burglarizing a West Sacramento home.  Not exactly the stuff that a Judicial Watch is made of, except for the fact that the only real evidence linking him to the burglary is a partial print of a palm.

As the defense attorney, Deputy Public Defender Amber Poston, argued in her opening statement, fingerprint analysis is not the exact science that it is portrayed on TV.  Indeed, there is no standard for testing.

The police found four prints on the burglarized residence but only one, that of a palm print (not the whole palm print, but part of a palm print) was found and matched to Mr. Barientos.

The critical question is: was Mr. Barrientos’ palm print really found on the window of the burglarized residence, or did the police believe it was Mr. Barientos for other reasons and draw a faulty conclusion?

That is the question the jury must answer.  But for us, the question is whether fingerprint analysis is really based on the kind of hard science that fingerprint experts claim.

According to one attorney’s newsletter, “Fingerprint experts believe that fingerprint patterns never change and are unique to each individual. For this reason, state and federal judges do not usually question their evidentiary validity. Juries typically agree when such evidence suggests an individual is guilty of committing a crime. At times, such evidence is so convincing that individuals accused of crimes confess when confronted with a ‘match.’ “

But then we have cases like the 2004 case of Brandon Mayfield.  Does the name ring a bell?  Well Mr. Mayfield was a 37-year-old lawyer living in Portland, Oregon.  In 2004, he was arrested for two weeks, after the FBI discovered his fingerprint on a bag of detonators recovered after the deadly Madrid train bombing that killed 191 people.

On the basis of the fingerprint, Mr. Mayfield was arrested and sent to jail.  The only problem is that the fingerprint was not Mr. Mayfield’s at all.

Wrote Slate Magazine back in 2004, “In the affidavit, [FBI Special Agent Richard] Werder was unequivocal about whose fingerprint was on the bag—it was Mayfield’s. ‘The FBI lab stands by their conclusion of a 100-percent positive identification,’ was the way the print match was described.”

They continued, “Botched forensics, whether they result from oversight, sloppiness, ego, or malice can easily sink an innocent defendant who might be ill-equipped and sometimes unable to unscramble the convincing, if false, forensic hash cooked up by the government. And with fingerprint evidence, often elevated to ‘smoking gun’ status by our culture and our courts, the chance for serious mischief is greatly increased.”

Why did they mess up?

“The confusion, said Robert Jordan, the FBI agent in charge of Oregon, resulted from analyzing an image of substandard quality.”

However, as Slate argued, “One of the most frightening consequences of the Mayfield incident is the bureau’s attempt to explain away Mayfield’s total misidentification by blaming it on a bad digital print. The reality is that it’s not the print that’s bad, it’s the science.”

The article continued, arguing that the problem was not the print but the practices.  The FBI analyzed not the original print but a digital copy.  And “the use of digital prints isn’t at all unusual. The FBI has already admitted that they regularly use digital images of fingerprints, and that, in this case ‘it was absolutely acceptable to examine a digital image.’ “

The article continued further, “For generations, and until DNA came along, fingerprint evidence has been touted as the ultimate forensic tool. So unique and special are our fingerprints that DNA itself is often described as a ‘genetic fingerprint.’ And that essential truth remains.”

Here is the core, and this is what we need to remember when evaluating our own case: “Done correctly, fingerprint analysis can be a powerful forensic tool of identification. The problem is that there aren’t universal standards for what ‘done correctly’ means.”

The Slate article then explained how fingerprint matches are done and the problem with that system:

“Fingerprint matches are made on the basis of what’s known as “points of comparison,” as a quick look at your thumb will demonstrate. What you will see are the friction ridges that comprise your unique fingerprint. The friction ridges whirl and spit, creating unique patterns that ultimately become the biometric data every burglar loves to hate. Comparing prints is a matter of looking for places where the ridges join or split—something that can be compared between prints. These points of comparison are used to both exclude prints (prove they are not the same) and to match prints.”

Here’s the problem: “The problem is this: Print examiners and even the computers that do the preliminary scans don’t actually match the entire print. In deciding if a print matches they almost always decide on the basis of a partial analysis.”

They use a system called the Integrated Automated Fingerprint Identification System or IAFIS.  Once the IAFIS finds a match, it spits it out but then the human has to take over.

There lies the weak point.  As the lawyers wrote, “Mistakes in identification may occur because the actual determination of a match is based on human inspection, a process many deem to be an imperfect science.”

Moreover, as the SLATE article pointed out, there is no national standard.

Indeed this is BY DESIGN.  Wrote the lawyers, “In fact, the International Association for Identification (IAI), an organization considered by many experts as the authority for fingerprint analysis certification, determined in 1973 that there is no need to require a set formula or standard in order to prove a fingerprint match. Specifically, it stated that ‘no valid basis exists to require a predetermined number of characteristics to exist between two fingerprint impressions in order to establish positive identity.’ “

Bottom line, they argued, there is no uniform definition of a match, and many states disagree on how many points of similarity are needed before declaring the existence of a match.

Wrote the Innocence Project of Florida on their blog, “Television’s CSI this is not. Despite all that technology, it then falls to fallible human beings to step in and make visual comparisons and the ultimate judgment calls on matches.”

The blogger continued, “I had already considered fingerprint analysis a junk science. Human examination is the key method to matching fingerprints and humans make errors, as previous cases and the article demonstrate.”

They reported on a study done by cognitive scientists in which five internationally respected fingerprint analysts were given the same print twice, but received different information about the case each time.

Mostly, all of the test subjects changed their minds based on the information given.

They reported, “In Dror’s study with Charlton, the five experts were told they were seeing the erroneously matched fingerprints of Brandon Mayfield, the Oregon man once linked to 2004’s terrorist  train bombings in Madrid. That he’d been wrongly accused based on fingerprint misidentification was widely known, thus suggesting what an expert determination would be.  What they were actually seeing, however, were fingerprints from other cases that they’d made determinations about years before.”

The blogger wrote, “Dror’s study proves what we already knew – that humans are inconsistent and capable of making mistakes.”

That does not even get into the problems such as reported in 2007 by the LA Times. “The Los Angeles Police Department has acknowledged in a confidential report that people have been falsely implicated in crimes because the department’s fingerprint experts wrongly identified them as suspects.”

The Times continued, “The 10-page internal report, obtained by The Times, highlighted two cases in which criminal defendants had charges against them dropped after problems with the fingerprint analysis  were exposed. LAPD officials do not know how many other people might have been wrongly accused over the years as a result of poor fingerprint analysis and do not have the funds to pay for a comprehensive audit to find out, according to police records and interviews.”

“This is something of extraordinary concern,” said Michael Judge, public defender for Los Angeles County. “Juries tend to accord the highest level of confidence to fingerprint evidence. This is the type of thing that easily could lead to innocent people being convicted.”

The article continued, “Sims-Lewis and other department officials, however, described a poorly-run operation, in which records and evidence were left lying around or misplaced, and supervisors ‘were stuck in the old way of doing things.’ Pressed to explain the sloppy work of the unit, Yvette Sanchez-Owens, commanding officer of the Scientific Investigation Division, speculated that ‘people were reviewing the work of friends and just rubber stamping it without really reviewing it.’ “

This may offer a bit of solace to people in Yolo County, but it should not.  We have repeatedly watched trials where evidence was improperly stored, inappropriately disposed of, and much worse.  If LA has problems with their print analysis, what of West Sacramento and smaller communities?

The bottom line from this research seems to be that, unlike bullet-lead analysis, fingerprint science in essence is sound.  The problem is that the application of it is wrought with human error.

I do not want to make a judgment about the Barrientos case, since we have not heard the testimony and other evidence.  But one thing that seems concerning here is that, based on the research, bias may lead to false conclusions.  In other words, if one believes they have the right suspect, perhaps one finds a match where one should not have ordinarily.

This is definitely something to watch for in the trial that is set to continue throughout the week.

—David M. Greenwald reporting

Share:

About The Author

David Greenwald is the founder, editor, and executive director of the Davis Vanguard. He founded the Vanguard in 2006. David Greenwald moved to Davis in 1996 to attend Graduate School at UC Davis in Political Science. He lives in South Davis with his wife Cecilia Escamilla Greenwald and three children.

Related posts

13 thoughts on “The Myth of the Fingerprints: Is Fingerprint Analysis Science Another Discredited and Untested Forensic Technique?”

  1. Roger Rabbit

    This is true in all aspects of Law Enforcement. Good cops and good DA’s want to get the guilty person and once some good evidence leads to a good suspect, a loss of focus to look for other suspects diminishes. Human error, over zealous, strong beliefs and opinions all cloud objectivity, especially in emotional or high pressure cases.

    This is why it is so critical for a jury member to questions everything and to not accept everything from the DA or cops are fact or absolute truth. But in our system it is made so that the Judge, the DA, the Cops are all on the same team and the belief is that none of them could or would do something wrong, bad or untruthful. That belief gets a lot of jurors to buy into things that may not be as they seem.

    Some time this happens by accident and that is not good, but when it happens by design by the unethical or the crooked that is the real tragedy. Like many things when people find a way to justify bad behavior, so when the crooked get caught they claim error or mistake and then when the over zealous or trying too hard get caught, they claim mistake and no one believes them. Over time this cause a lack of trust in the system and when that is not corrected the only fix is a good outside investigation, which rarely happens since the system does not like to prove you can’t trust the system or the other fix is the people finally say enough is enough and just stop voting guilty when on jury duty. That is the clearest message to the system, it the people vote not guilty on all cases, that is a clear way to say we don’t the system and then things will change.

  2. biddlin

    Justice is always dependent on the truthfulness and honesty of the investigators, litigators, judges and jurors. When any one of those elements comes to a case with an agenda, justice is in jeopardy.
    Police and DA’s rely on convictions to solicit funding from federal and private grants. That gives them an agenda.
    Accused criminals have a constitutional right to vigorous representation and a protection against self-incrimination, that gives them and their lawyers an agenda.
    Judges have to face voters and may be swayed by political expediency. An agenda.
    That leaves jurors. Us.

  3. craised

    If someone is truly interested in palm prints and the accuracy of using palm print for identification purposes you might find this link interesting.

    [url]http://www.cse.msu.edu/biometrics/Publications/Palmprints/JainDemirkusOnLatentPalmprintMatching08.pdf[/url]

  4. E Roberts Musser

    dmg: “But for us, the question is whether fingerprint analysis is really based on the kind of hard science that fingerprint experts claim.”

    I’m not sure what you mean by “hard science”. No method is perfect, not even DNA evidence. The only way to refer to the different testing methods and their reliability is to talk about their statistical accuracy, and as we know there are “lies, damn lies, and then statistics”. Bottom line is no method for gathering scientific evidence is perfect and never will be. So the courts have decided to adopt certain methods as reliable enough to be admissable in court, and others as too unreliable and inadmissable. It is up to the defense to put the evidence through a rigorous test in court. It is up to the jury to decide how much weight to give to scientific evidence in any individual case. I think it would be more than helpful to adopt “uniform standards” for evidence analysis, but even that will not be foolproof, altho it may increase the degree of accuracy – depends on what standards are set.

    dmg: “The blogger wrote, “Dror’s study proves what we already knew – that humans are inconsistent and capable of making mistakes.””

    Really? Nothing like stating the obvious. But what is the conclusion – ergo we let all defendants off the hook bc the science that is used to prosecute criminals is inexact/imperfect? I SUSPECT (don’t have the data) in very few cases is there only one single piece of scientific evidence to convict a suspect. Usually there is more than a single piece of evidence. For instance, in the case in point, does the defendant have an alibi of where he was at the time of the crime? Does he have a criminal record (not admissable in court, but can be something the police use to determine if they should do a more careful fingerprint analysis)?

    dmg: “The Times continued, “The 10-page internal report, obtained by The Times, highlighted two cases in which criminal defendants had charges against them dropped after problems with the fingerprint analysis were exposed. LAPD officials do not know how many other people might have been wrongly accused over the years as a result of poor fingerprint analysis and do not have the funds to pay for a comprehensive audit to find out, according to police records and interviews.” “This is something of extraordinary concern,” said Michael Judge, public defender for Los Angeles County. “Juries tend to accord the highest level of confidence to fingerprint evidence. This is the type of thing that easily could lead to innocent people being convicted.””

    The problem with these sweeping statements is as described above: How many of those cases involving fingerprint analysis were based solely on fingerprint identification? That is the key question that should be answered by law enforcement in deciding whether to open up a past case…

    Bottom line – NO SCIENTIFIC METHOD IS FOOLPROOF. NONE.

  5. E Roberts Musser

    RR: “This is true in all aspects of Law Enforcement. Good cops and good DA’s want to get the guilty person and once some good evidence leads to a good suspect, a loss of focus to look for other suspects diminishes.”

    We often disagree, but on this point I am in absolute concurrence. How can we get law enforcement to be more objective when it comes to “getting their man”? I wish I knew the answer to that one – look at the Duke “rape” case as a prime example of a pre-conceived objective for political gain…

    RR: “This is why it is so critical for a jury member to questions everything and to not accept everything from the DA or cops are fact or absolute truth…”

    The problem is the prosecution wears the “cloak of authority” in which the jury may believe the DA has no reason to lie, but has every reason to get at the truth. The public often fails to understand the DA’s reputation is on the line in every case, since s/he is an elected official and citizens are more interested in a tough on crime stance than on justice being done. There is also a perception out there among many citizens that if the defendant was arrested for something, it is likely the suspect committed the crime. Again, the public needs to stop watching television shows so much, and needs more education as to the process. I would go so far as to say it would be wise for a prospective jury to watch an educational unbiased film ahead of time, to disabuse them of the notion that evidence gathering is perfect/that DA’s and the defense never shade the truth, the jury’s duty to really listen to the evidence and question every aspect of the case, etc.

    RR: “That is the clearest message to the system, it the people vote not guilty on all cases, that is a clear way to say we don’t the system and then things will change.”

    This is where you and I part company. Jury nullification is what happened in the O.J. Simpson case, and a vicious murderer walked free to do harm again (dealing drugs; beating his girlfriend, committing armed robbery). Jury nullification is not the answer either…

  6. jimt

    E Musser–your comments are spot on!

    With regard to fingerprint and palm print identification; it would be relatively easy to perform controlled studies to evaluate, using several different techniques using different match/mismatch criteria; and count up the percentage of false positive matches and false negatives, true matches, and uncertains; and do the associated statistics and confidence levels. Working from a database where true matches are known independently; but not revealed to the person doing the match/mismatch analyses (blind study).

  7. David M. Greenwald

    Elaine: I think the key point is this, you don’t need to let all defendants all the hook where there are finger print matches provided there is more evidence than that that they committed the crime. If there isn’t, fingerprint analysis alone may be and probably should be insufficient to convict someone.

    The danger lies when the circumstantial evidence is weak and the fingerprint evidence becomes one point among many to lead the jury towards a guilty verdict.

  8. E Roberts Musser

    dmg: So what are you saying here – fingerprint analysis should not be allowed in court bc it is inexact science? Or that there needs to be reform by instituting a “uniform federal standard” that requires more points of comparison than many states are currently using? It is not clear to me where you are coming down on this issue. As I said before, no scientific evidence is 100% and NEVER WILL BE. Does that mean we discard all scientific evidence as inexact? Or tighten up the requirements to ensure a certain degree of accuracy? An example of this is lie detector tests. Lie detector tests are deemed inadmissable bc statistically they are just not accurate enough. But it would seem to me that in fingerprint analysis, as jimt noted, it would be easy enough to run a blind study to determine how many points of comparison in a finger print must match to attain a certain statistically significant degree of accuracy that would satisfy even you…

  9. jonlancaster

    What I get from this article is that there needs to be further automation in fingerprint analysis.

    DNA analysis is highly automated with a small chance of human error.

    Everyone involved in the investigation, processing of evidence and prosecution of cases has a strong vested interest in “winning”. It’s the “winning” that gets cops promoted, CSI grants funded, ADA’ promoted, etc.

    They are all assumed to be honest people with no agenda besides “truth and justice”, which we all know is sadly a huge lie.

    And this is where the problems begin. The presumption of guilt and the human factors involved in this consensus of guilt that bootstraps it’s way from cops to evidence techs to DA’s.

    All to often are alternative theorys of the crime and other possible suspects investigated…takes to much time & money.

    More automation may not be the best answer, but removing human’s goal to “win” from the process is always a good thing in my book…

  10. jonlancaster

    meant to say “All to often are alternative theorys of the crime and other possible suspects NOT investigated…takes to much time & money.”

  11. E Roberts Musser

    jonlancaster: “More automation may not be the best answer, but removing human’s goal to “win” from the process is always a good thing in my book…”

    Well said. Just remember, nothing is foolproof…

Leave a Reply

X Close

Newsletter Sign-Up

X Close

Monthly Subscriber Sign-Up

Enter the maximum amount you want to pay each month
$ USD
Sign up for