California Court upholds fingerprint evidence

[bficken]

Interesting read out of an appellate court in California.

http://www.courts.ca.gov/opinions/documents/C072621.PDF

[g.]

Wow. Thank-you Cali for upholding fingerprint evidence admissibility. Unfortunately, I am not sure I want you advocating for the science.

I trimmed some highlights for you all...

PS - Can anyone tell me why the document has "YOLO" at top under the title/district name??? Kinda funny.


In O.D., the fingerprint analysts used the ACE-V method (analysis, comparison, evaluation, verification). (O.D., supra, 221 Cal.App.4th at p. 1004.) The O.D. court found that “the Kelly rule is inapplicable to the ACE-V method of fingerprint comparison because, regardless whether it is generally accepted, fingerprint comparison is not the type of scientific technique Kelly governs since it can easily be understood by nonexperts and is unlikely to convey a misleading aura of certainty.]” “Our Supreme Court, in [People v.] Venegas [(1998) 18 Cal.4th 47], expressly distinguished DNA evidence, which is subject to Kelly, from ‘fingerprint, shoe track, bite mark, or ballistic comparisons, which [laypersons] essentially can see for themselves.

Finally, the O.D. court wrote: “[The fingerprint expert’s] testimony was particularly unlikely to convey a misleading aura of certainty because [she] openly acknowledged that fingerprint comparisons are inherently subjective and that no study establishes their infallibility. She also made clear that it was her opinion – not an established scientific fact – that the palm print [at the crime scene] matched [the minor’s].

‘When a witness gives [her] personal opinion on the stand – even if [she] qualifies as an expert – [laypersons] may temper their acceptance of [her] testimony with a healthy skepticism born of their knowledge that all human beings are fallible.

…As the O.D. court noted, fingerprint evidence is not subject to exclusion based on a challenge to its reliability because it is not a new scientific technique and it does not convey a misleading aura of certainty. As the Supreme Court has held, the jury can observe the fingerprints and make its own comparison to determine for itself the similarities.

A defendant may respond to fingerprint evidence by challenging the training of the fingerprint expert (which defendant Valadez did in this case), by challenging the process by which the fingerprint expert made the comparison (which defendant Valadez did in this case to some extent), or by showing that the fingerprints do not match, either by calling the defense’s own expert or simply showing the jury where they do not match (which defendant Valadez apparently did not do here).

…. That’s not to say that fingerprint matching is as reliable as DNA evidence, for example. Forensic DNA analysis involves comparing a strand of DNA (the genetic code) from the suspect with a strand of DNA found at the crime scene. The comparison is done with scientific instruments and determines whether the segments are chemically identical. Errors are vanishingly rare provided that the strands of code are reasonably intact.” (Herrera, supra, 704 F.3d at p. 485.)

“Chemical [DNA] tests can determine whether two alleles are identical, but a fingerprint analyst must visually recognize and classify the relevant details in the latent print – which is difficult if the print is incomplete or smudged. ‘[T]he assessment of latent prints from crime scenes is based largely on human interpretation. . . . [T]he process does not allow one to stipulate specific measurements in advance, as is done for a DNA analysis. Moreover, a small stretching of distance between two fingerprint features, or a twisting of angles, can result from either a difference between the fingers that left the prints or from distortions from the impression process.’

Matching latent fingerprints is thus a bit like an opinion offered by an art expert asked whether an unsigned painting was painted by the known painter of another painting; he makes or rejects a match on the basis of visual evidence. Eyewitness evidence is similar. The eyewitness saw the perpetrator of a crime. His recollection of the perpetrator’s appearance is analogous to a latent fingerprint. He sees the defendant at the trial – that sighting is analogous to a patent fingerprint. He is asked to match his recollection against the courtroom sighting – and he is allowed to testify that the defendant is the perpetrator, not just that there is a close resemblance. A lineup, whether photo or in-person, is a related method of adducing matching evidence, as is handwriting evidence.

Matching evidence of the kinds that we’ve just described, including fingerprint evidence, is less rigorous than the kind of scientific matching involved in DNA evidence; eyewitness evidence is not scientific at all. But no one thinks that only scientific evidence may be used to convict or acquit a defendant. The increasingly well documented fallibility of eyewitness testimony, has not banished it from criminal trials.

The probability of two people in the world having identical fingerprints is not known, but it appears to be extremely low. The great statistician Francis Galton estimated the probability as 1 in 64 billion. That was not an estimate of the probability of a mistaken matching of a latent to a patent or another latent fingerprint. Yet errors in such matching appear to be very rare, though the matching process is judgmental rather than scientifically rigorous because it depends on how readable the latent fingerprint is and also on how distorted a version of the person’s patent fingerprint it is.

[SConner]

Yolo County, near Sacramento no less!

[L.J.Steele]

Matching latent fingerprints is thus a bit like an opinion offered by an art expert asked whether an unsigned painting was painted by the known painter of another painting; he makes or rejects a match on the basis of visual evidence. Eyewitness evidence is similar. The eyewitness saw the perpetrator of a crime. His recollection of the perpetrator’s appearance is analogous to a latent fingerprint. He sees the defendant at the trial – that sighting is analogous to a patent fingerprint. He is asked to match his recollection against the courtroom sighting – and he is allowed to testify that the defendant is the perpetrator, not just that there is a close resemblance. A lineup, whether photo or in-person, is a related method of adducing matching evidence, as is handwriting evidence.

I'm not sure if I'm more concerned about how badly this mis-states the complexity and research into of eyewitness ID evidence or the series of mangled comparisons to fingerprints. Wow!