At the February 2018 American Academy of Forensic Science meeting, DOJ Deputy Attorney General Rod Rosenstein announced the Uniform Language for Testimony and Reporting (ULTR) document for fingerprints. The purpose of the document is to standardize language used by Department of Justice fingerprint examiners in their reports and testimony. While the document does not apply to examiners in state or local laboratories, it is important for legal practitioners to understand what standards exist in the field. While the new language makes some advances by limiting some past overstatements (such as prohibiting examiners from saying “two friction ridge prints originated from the same source to the absolute exclusion of all other sources;” using terms like “individualize” or “reasonable degree of scientific certainty;” expressing 100% certainty; or implying that fingerprint examination has a zero error rate), it still goes beyond what the data support.
The American Association for the Advancement of Science (AAAS) CEO Rush Holt responded by stating in a letter to Deputy Attorney General Rosenstein,
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. As there is no empirical basis for examiners to estimate the frequency of any particular pattern observable in a print, the term identification or, in your proposed language source identification, should not be used.
The AAAS comments rely on the Forensic Science Assessments – A Quality and Gap Analysis: Latent Fingerprint Examination report published in September 2017 which addressed the validity and reliability of latent fingerprint examinations.