6 ms·

Fingerprinting is junk science. Polygraphs are junk science. Tons of things that have been or are admissible as evidence are junk science.

by wyager 5y ago

giantg2 5y ago
I wouldn't call polygraphs forensics. Most states do not allow them as evidence. Do you have a link for the fingerprinting claim?
- monetus 5y ago
  (Not who you responded to) https://www.crammlawfirm.com/fingerprint-match-jails-innocent-man/ https://www.crammlawfirm.com/fingerprint-match-jails-innocen... This isn't the case I originally recalled, and doesn't say how many points were matched, but I remember a 5 point match being used to convict a person who was later proven innocent.
  - newswasboring 5y ago
    That shows its flawed, not junk.
  - giantg2 5y ago
    Oh, yeah. I've heard of them using too few points. I would have lumped that into misconduct or mistakes by the lab tech or prosecution.
    - monetus 5y ago
      Yeah, knowing or not, comparing with too few points is misconduct - that should be the fault of someone besides the defense, but that is somewhat tangential - does anyone with more knowledge know where the line is drawn? I imagine there are some outlandish coincedences happening.
  - arp242 5y ago
    Fingerprints aren't "junk science", but they do have error margins and plenty of room for mistakes. The problem is that many juries, judges, prosecutors, and even defenders forget about this. This is the case for many types of evidence; witness statements for example can also be notoriously unreliable. It's not bad to use this kind of evidence, but you do have a problem if you consider any witness statement to be absolute truth and never consider any "reasonable doubt" there may be, and this is how you end up convicting people based purely on "I saw the suspect commit the crime from 50 metres away in the dark and I'm sure it was him!" or some such. If you have six independent witness statements like that, or a witness statement and fingerprints then the reasonable doubt starts becoming a lot less reasonable. This is also the problem with the case in this article: a piece of evidence over which it seems like reasonable doubt should exists is the singular piece of evidence tying this person to the crime. The problem here isn't the evidence as such IMHO, but that juries and/or defenders (depends on the case) seem exceedingly bad at sceptically examining physical evidence.
    - dragonwriter 5y ago
      > Fingerprints aren't "junk science" Fingerprints are directly-recorded facts. What may be junk science is what expert witnesses present about the interpretation of fingerprints. > The problem is that many juries, judges, prosecutors, and even defenders forget about this. Juries as triers of fact, and judges insofar as they are ruling on the facts of the case, aren't, in any case, supposed to allow themselves fo be guided by extrinsic knowledge, they are supposed to act based on facts (both direct and the expert knowledge relating to the import of direct facts) provided as evidence, both testimony and exhibits, in the case.
      - arp242 5y ago
        > Fingerprints are directly-recorded facts. That's not really how it works; false positives exist, especially if you consider that a lot of times you have incomplete or smudged fingerprints and there is actually some amount of subjectivity involved in determining a match. See e.g. [1]: "only two properly designed studies of latent fingerprint analysis had been conducted. These both found the rate of false matches (known as “false positives”) to be very high: 1 in 18 and 1 in 30." Again: useful evidence for sure, but considering them undisputable facts is not wise. [1]: https://theconversation.com/fingerprinting-to-solve-crimes-not-as-robust-as-you-think-85534 https://theconversation.com/fingerprinting-to-solve-crimes-n...
- k1t 5y ago
  Not fingerprinting, but related issue for microscopic hair comparisons: The Justice Department and FBI have formally acknowledged that nearly every examiner in an elite FBI forensic unit gave flawed testimony in almost all trials in which they offered evidence against criminal defendants over more than a two-decade period before 2000. Of 28 examiners with the FBI Laboratory’s microscopic hair comparison unit, 26 overstated forensic matches in ways that favored prosecutors in more than 95 percent of the 268 trials reviewed so far https://www.washingtonpost.com/local/crime/fbi-overstated-forensic-hair-matches-in-nearly-all-criminal-trials-for-decades/2015/04/18/39c8d8c6-e515-11e4-b510-962fcfabc310_story.html https://www.washingtonpost.com/local/crime/fbi-overstated-fo...
tzs 5y ago
> Fingerprinting is junk science. How then do you explain the success of Touch ID on Apple devices and the equivalent systems on other phones and tablets? Random people can't just walk up and unlock a Touch ID device with their fingerprint, which suggests that fingerprints are in fact a very good way to tell people apart. Yes, it is possible to make a fake fingerprint that Touch ID will not be able to distinguish from my fingerprint. But that fake fingerprint will only unlock my device, not your device, so it is still correctly distinguishing our fingerprints.
- BoorishBears 5y ago
  Because other surfaces are not a purpose built sensor designed to detect the features of a finger then repeatedly trained with a specific set of finger scans? Like are you joking? Saying TouchID validates fingerprinting is like saying MRI machines validate psychics.
  - giantg2 5y ago
    Are you joking? It seems you two have a different idea of what is being discussed. The underlying fundamentals of finger prints are solid. The part that can make them ineffective is when they are using insufficiently tested tools or matching on too few points. And of course misrepresentating what a match actually means and how it pertains to the case.
    - z3ncyberpunk 5y ago
      I can effectively burn off my fingerprints completely... They are not completely effective at all
    - DSMan195276 5y ago
      > The underlying fundamentals of finger prints are solid. What exactly are these underlying 'fundamentals'? Nobody even knows if everybody has unique fingerprints, it's just an assumption. Beyond that, it's not all that relevant since as you mentioned how the matching is done is largely subjective, and it depends a lot on the number of "points" used and who does the matching, and that should really bring the accuracy even more into question. What exactly is the statistical probability of an incorrect match based on the number of points used? Good luck answering that question. IMO the situation is made a lot worse by the fact that the public generally assumes fingerprinting to be extremely accurate (or 100% accurate).

Fingerprinting is junk science. Polygraphs are junk science. Tons of things that have been or are admissible as evidence are junk science.

by wyager 5y ago

Fingerprinting is junk science. Polygraphs are junk science. Tons of things that have been or are admissible as evidence are junk science.

giantg2 5y ago

I wouldn't call polygraphs forensics. Most states do not allow them as evidence. Do you have a link for the fingerprinting claim?

monetus 5y ago
(Not who you responded to) https://www.crammlawfirm.com/fingerprint-match-jails-innocent-man/ https://www.crammlawfirm.com/fingerprint-match-jails-innocen... This isn't the case I originally recalled, and doesn't say how many points were matched, but I remember a 5 point match being used to convict a person who was later proven innocent.
- newswasboring 5y ago
  That shows its flawed, not junk.
- giantg2 5y ago
  Oh, yeah. I've heard of them using too few points. I would have lumped that into misconduct or mistakes by the lab tech or prosecution.
  - monetus 5y ago
    Yeah, knowing or not, comparing with too few points is misconduct - that should be the fault of someone besides the defense, but that is somewhat tangential - does anyone with more knowledge know where the line is drawn? I imagine there are some outlandish coincedences happening.
- arp242 5y ago
  Fingerprints aren't "junk science", but they do have error margins and plenty of room for mistakes. The problem is that many juries, judges, prosecutors, and even defenders forget about this. This is the case for many types of evidence; witness statements for example can also be notoriously unreliable. It's not bad to use this kind of evidence, but you do have a problem if you consider any witness statement to be absolute truth and never consider any "reasonable doubt" there may be, and this is how you end up convicting people based purely on "I saw the suspect commit the crime from 50 metres away in the dark and I'm sure it was him!" or some such. If you have six independent witness statements like that, or a witness statement and fingerprints then the reasonable doubt starts becoming a lot less reasonable. This is also the problem with the case in this article: a piece of evidence over which it seems like reasonable doubt should exists is the singular piece of evidence tying this person to the crime. The problem here isn't the evidence as such IMHO, but that juries and/or defenders (depends on the case) seem exceedingly bad at sceptically examining physical evidence.
  - dragonwriter 5y ago
    > Fingerprints aren't "junk science" Fingerprints are directly-recorded facts. What may be junk science is what expert witnesses present about the interpretation of fingerprints. > The problem is that many juries, judges, prosecutors, and even defenders forget about this. Juries as triers of fact, and judges insofar as they are ruling on the facts of the case, aren't, in any case, supposed to allow themselves fo be guided by extrinsic knowledge, they are supposed to act based on facts (both direct and the expert knowledge relating to the import of direct facts) provided as evidence, both testimony and exhibits, in the case.
    - arp242 5y ago
      > Fingerprints are directly-recorded facts. That's not really how it works; false positives exist, especially if you consider that a lot of times you have incomplete or smudged fingerprints and there is actually some amount of subjectivity involved in determining a match. See e.g. [1]: "only two properly designed studies of latent fingerprint analysis had been conducted. These both found the rate of false matches (known as “false positives”) to be very high: 1 in 18 and 1 in 30." Again: useful evidence for sure, but considering them undisputable facts is not wise. [1]: https://theconversation.com/fingerprinting-to-solve-crimes-not-as-robust-as-you-think-85534 https://theconversation.com/fingerprinting-to-solve-crimes-n...
k1t 5y ago
Not fingerprinting, but related issue for microscopic hair comparisons: The Justice Department and FBI have formally acknowledged that nearly every examiner in an elite FBI forensic unit gave flawed testimony in almost all trials in which they offered evidence against criminal defendants over more than a two-decade period before 2000. Of 28 examiners with the FBI Laboratory’s microscopic hair comparison unit, 26 overstated forensic matches in ways that favored prosecutors in more than 95 percent of the 268 trials reviewed so far https://www.washingtonpost.com/local/crime/fbi-overstated-forensic-hair-matches-in-nearly-all-criminal-trials-for-decades/2015/04/18/39c8d8c6-e515-11e4-b510-962fcfabc310_story.html https://www.washingtonpost.com/local/crime/fbi-overstated-fo...

tzs 5y ago

> Fingerprinting is junk science. How then do you explain the success of Touch ID on Apple devices and the equivalent systems on other phones and tablets? Random people can't just walk up and unlock a Touch ID device with their fingerprint, which suggests that fingerprints are in fact a very good way to tell people apart. Yes, it is possible to make a fake fingerprint that Touch ID will not be able to distinguish from my fingerprint. But that fake fingerprint will only unlock my device, not your device, so it is still correctly distinguishing our fingerprints.

BoorishBears 5y ago
Because other surfaces are not a purpose built sensor designed to detect the features of a finger then repeatedly trained with a specific set of finger scans? Like are you joking? Saying TouchID validates fingerprinting is like saying MRI machines validate psychics.
- giantg2 5y ago
  Are you joking? It seems you two have a different idea of what is being discussed. The underlying fundamentals of finger prints are solid. The part that can make them ineffective is when they are using insufficiently tested tools or matching on too few points. And of course misrepresentating what a match actually means and how it pertains to the case.
  - z3ncyberpunk 5y ago
    I can effectively burn off my fingerprints completely... They are not completely effective at all
  - DSMan195276 5y ago
    > The underlying fundamentals of finger prints are solid. What exactly are these underlying 'fundamentals'? Nobody even knows if everybody has unique fingerprints, it's just an assumption. Beyond that, it's not all that relevant since as you mentioned how the matching is done is largely subjective, and it depends a lot on the number of "points" used and who does the matching, and that should really bring the accuracy even more into question. What exactly is the statistical probability of an incorrect match based on the number of points used? Good luck answering that question. IMO the situation is made a lot worse by the fact that the public generally assumes fingerprinting to be extremely accurate (or 100% accurate).