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What does the President of the United States have to do with forensic science?\u00a0 Answering that could take one, indirectly, back to Abraham Lincoln, who signed the legislation that led to the creation of the National Academy of Sciences.\u00a0 The NAS, in 2009, issued a report that called into question the validity and precision of many forensic disciplines.\u00a0 That report was STRENGTHENING FORENSIC SCIENCE: A PATH FORWARD.<\/p>\n
But today the connection is more direct.\u00a0 An important part of the advisory apparatus available to President Obama is PCAST, the President\u2019s Advisory Council on Science and Technology.\u00a0 And PCAST\u2019s September, 2016 report FORENSIC SCIENCE IN CRIMINAL COURTS: ENSURING SCIENTIFIC VALIDITY OF FEATURE-COMPARISON METHODS –\u00a0 by some of this nation\u2019s preeminent scientists \u2013 presented \u201cfindings concerning the \u2018foundational validity\u2019 of the indicated methods as well as their \u2018validity as applied\u2019 in practice in the courts\u2026\u201d<\/p>\n
And why should judges and lawyers care?\u00a0 The Report shows that there are concerns even with the most highly-regarded of forensic disciplines \u2013 DNA analysis; and that those farther down the scientific ladder (and some clearly non-scientific) have even more foundational problems.<\/p>\n
The word \u201cfoundational\u201d is the focus of the Report.\u00a0 It is the metric of assessing:<\/p>\n
that a method has been subjected to empirical <\/em>testing by multiple groups, under conditions appropriate to its intended use. The studies must (a) demonstrate that the method is repeatable and reproducible and (b) provide valid estimates of the method\u2019s accuracy (that is, how often the method reaches an incorrect conclusion) that indicate the method is appropriate to the intended application.<\/p>\n The Report highlighted a second and related concern.\u00a0 PCAST emphasizes that \u201c[w]ithout appropriate estimates of accuracy, an examiner\u2019s statement that two samples are similar\u2014or even indistinguishable\u2014is scientifically meaningless: it has no probative value, and considerable potential for prejudicial impact. \u201c<\/p>\n Whether \u201cscientifically meaningless\u201d will translate into judicially \u201cinadmissible\u201d remains to be seen.<\/p>\n And how did the disciplines assessed by the Report fare?\u00a0 Discussed here are five prominent fields.<\/p>\n DNA:<\/strong><\/p>\n There is foundational validity for single-source [DNA evidence coming from only one person] and simple mixtures where there is DNA from two individuals.\u00a0 However, where the mixture contains DNA from three or more persons, \u201cstudies have established the foundational validity of some objective methods under limited circumstances (specifically, a three-person mixture in which the minor contributor constitutes at least 20 percent of the intact DNA in the mixture) but that substantially more evidence is needed to establish foundational validity across broader settings.\u201d<\/p>\n And the meaning of this?\u00a0 A judge must be hesitant in permitting conclusions about whether a DNA profile corresponding to that of a known individual is contained within a complex mixture of biological evidence.<\/p>\n LATENT PRINT [FINGERPRINT] EVIDENCE<\/strong><\/p>\n Latent print examination received some support in the Report; it was deemed to have foundational validity but with \u201ca false positive rate that is substantial and is likely to be higher than expected by many jurors based on longstanding claims about the infallibility of fingerprint analysis. The false-positive rate could be as high as 1 error in 306.\u201d\u00a0 Unmentioned in the report is the separate issue of whether the ultimate conclusion \u2013 that a print did<\/em> come from an individual and no one else \u2013 has a clear scientific basis and what number or constellation of features suffices to make that call.\u00a0 The Report also emphasized the subjective nature of the analysis, the risk of biasing information distorting the analysis, and the need for more \u201crigorous\u201d proficiency testing to ensure that any individual analyst\u2019s assessment deserves being credited.<\/p>\n Firearms:<\/strong><\/p>\n Here, the Report found some but insufficient research to show foundational validity.\u00a0 The Report emphasizes that whatever current data about error rates are available need to be disclosed if<\/em> courts permit firearms comparison testimony.\u00a0 Again, the Report notes concerns about the potential for cognitive bias and the need for proficiency testing.<\/p>\n Footwear Analysis:<\/strong><\/p>\n The Report is clear and concise here, finding no<\/em> validity to matching testimony that\u00a0 \u201cassociate[s] shoeprints with particular shoes based on specific identifying marks. Such associations are unsupported by any meaningful evidence or estimates of their accuracy and thus are not scientifically valid.\u201d<\/p>\n Bitemark Analysis:<\/strong><\/p>\n Perhaps the most damning words were saved for this field.\u00a0 \u201cPCAST considers the prospects of developing bitemark analysis into a scientifically valid method to be low.\u00a0 We advise against devoting significant resources to such efforts.\u201d<\/p>\n <\/p>\n Responses to the Report have varied in tone.\u00a0 Judge Alex Kozinski, who served as an advisor to its preparation, has written in stark terms that \u201c[o]nly the most basic form of DNA analysis is scientifically reliable, the study indicates. Some forensic methods have significant error rates and others are rank guesswork.\u201d\u00a0 In slightly more muted terms, Judge Harry Edwards and Law School Dean Jennifer Mnookin, also advisors, wrote that \u201c[t]he report finds that many forensic techniques do not yet pass scientific muster. This strongly implies these techniques are not ready for use in the courtroom either.\u201d<\/p>\n The view from the prosecution side has been to the contrary, and terribly dismissive.\u00a0 The National District Attorneys Association released a press statement that \u201cthe opinions expressed by PCAST in their report clearly and\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 obviously disregard large bodies of scientific evidence to the contrary and rely, at times, on unreliable\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 and discredited research.\u201d\u00a0 It decries the report as \u201cscientifically irresponsible\u201d and that adopting \u201cany\u201d of its recommendations would have a \u201cdevastating effect\u201d on law enforcement.<\/p>\n For the judiciary, what does this mean?\u00a0 At a minimum, a judge must decide whether the Reports conclusions have merit and, if so, to be proactive and inquire into a discipline\u2019s \u201cfoundational validity,\u201d practitioner proficiency, risk of biasing information, and error rate, and then determine admissibility and scope of testimony; or weigh these factors if<\/em> prompted by a motion to exclude or limit forensic discipline testimony.<\/p>\n If doing so, particular attention should be paid to terminology used by an expert.\u00a0 As the Report emphasizes,<\/p>\n courts should never permit scientifically indefensible claims such as: \u201czero,\u201d \u201cvanishingly small,\u201d \u201cessentially zero,\u201d \u201cnegligible,\u201d \u201cminimal,\u201d or \u201cmicroscopic\u201d error rates; \u201c100 percent certainty\u201d or proof \u201cto a reasonable degree of scientific certainty;\u201d identification \u201cto the exclusion of all other sources;\u201d or a chance of error so remote as to be a \u201cpractical impossibility.\u201d<\/p>\n Judges will also have to assess whether the Report itself is admissible as a Government Report under Rule 803(8).\u00a0 If so, it becomes \u2018evidence\u2019 on its own for both an admissibility hearing and trial, as well as a document appropriate for examining witnesses.<\/p>\n And lawyers?\u00a0 The fundamental obligation is clear.\u00a0 It is to learn both the strengths of every forensic discipline and its limits, and to bring science to their understanding of evidence before it is presented in the courtroom.<\/p>\n [NOTE:\u00a0 A link to the Report may be found at \u00a0 \u00a0https:\/\/www.whitehouse.gov\/blog\/2016\/09\/20\/pcast-releases-report-forensic-science-criminal-courts . This author is also a member of the National Commission on Forensic Science.\u00a0 The views expressed here are solely his own and are not intended to represent the views of the Attorney General, the United States Department of Justice, or any government entity or agency.<\/strong>]<\/p>\n <\/p>\n <\/p>\n","protected":false},"excerpt":{"rendered":" What does the President of the United States have to do with forensic science?\u00a0 Answering that could take one, indirectly, back to Abraham Lincoln, who signed the legislation that led to the creation of the National Academy of Sciences.\u00a0 The NAS, in 2009, issued a report that called into question the validity and precision<\/p>\n","protected":false},"author":31,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"generate_page_header":"","_jetpack_memberships_contains_paid_content":false,"footnotes":""},"categories":[2,3,6,7],"tags":[],"coauthors":[238],"class_list":["post-1806","post","type-post","status-publish","format-standard","hentry","category-advocacy","category-advocacy-and-evidence-blog","category-criminal-law","category-evidence"],"yoast_head":"\n