Forensic Science – Fingerprint Comparison Reporting Guidelines

New updated information on fingerprint science and reporting results in courtrooms by the U.S. Department of Justice.

Do not let the State or Government offer this of forensic science evidence against you, or your client, without making the reasonable educated challenge to its use and weight.

I think this is great information for a motion in limine to exclude the use of the term ‘identification’ alone, exclude the use of the phrase ‘to the exclusion of all others’, and to exclude the assertion that there is a ‘zero error rate’ in fingerprint analysis.

United States Department of Justice, APPROVED Uniform Language for Testimony and Reports for the Forensic Latent Print Discipline

  • “An examiner shall not assert that two friction ridge impressions originated from the same source to the exclusion of all other sources or use the terms ‘ individualize’ or ‘ individualization. ‘ This may wrongly imply that a source identification is based upon a statistically-derived or verified measurement or comparison of all friction ridge skin impression features in the world’s population, rather than an examiner’s conclusion.
  • An examiner shall not assert a 100% level of certainty in his/her conclusion, or otherwise assert that it is numerically calculated.
  • An examiner shall not assert that latent print examination is infallible or has a zero error rate.
  • An examiner shall not cite the number of latent print comparisons performed in his or her career as a measure for the accuracy of a conclusion offered in the instant case.
  • An examiner shall not use the expressions ‘reasonable degree of scientific certainty,’ ‘reasonable scientific certainty,’ or similar assertions of reasonable certainty as a description of the confidence held in his or her conclusion in either reports or testimony unless required to do so by a judge or applicable law.”

FULL TEXT:

https://www.justice.gov/file/1037171/download

Letter of Rush Holt, Chief Executive Officer of American Association for the Advancement of Science.

“There is no scientific basis for estimating the number of individuals who might have a particular pattern of features; therefore, there is no scientific basis on which an examiner might form an expectation of whether an arrangement comes from the same source. The proposed language fails to acknowledge the uncertainty that exists regarding the rarity of particular fingerprint patterns. Any such expectations that an examiner asserts necessarily rest on speculation, rather than scientific evidence.”

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