Document Category: Forensics

This motion seeks exclusion of firearm and toolmark identification evidence under Daubert and Michigan Rule of Evidence 702, arguing that the AFTE method lacks foundational scientific validity and relies on subjective, unarticulated examiner judgment. Drawing on the National Academy of Sciences and President’s Council of Advisors on Science and Technology reports, the motion explains that the field lacks standardized protocols, reproducible methods, and reliable error rates, with some studies documenting false positive rates as high as 11.2 percent. The motion further argues that such evidence misleads jurors by cloaking opinion testimony as scientific and should also be excluded under Rule 403. Defenders can use this motion to demand Daubert hearings, limit examiner testimony, or seek outright exclusion of firearm and toolmark evidence.

Because each stage of Facial Recognition (FR) carries a risk of error, due process and Brady require disclosure concerning every step (pp. 6–7). The five steps are: (1) the probe photo used, (2) the database selected, (3) any photo editing performed, (4) the algorithmic search, and (5) human review (pp. 6, 9–13). The brief explains that FR has particularly high error rates when applied to people of color, women, elders, and children (p. 8). Low-quality or edited probe photos increase error (pp. 10–11), and many FR databases are skewed by overrepresentation of minorities (pp. 12–13). Algorithms operate as “black boxes” with differing reliability (p. 13), while human review is subject to the same biases as eyewitness identification (p. 13). Because the risk of error varies at each stage and may be exculpatory, defense counsel is entitled to full discovery of the FR process, including the algorithm and analyst, both of whom function as impeachable “witnesses” (pp. 26–27). Defenders can use this brief to argue for comprehensive discovery of FR methods and to frame challenges to the admissibility or reliability of FR-based identifications.

This motion describes social science research about the fallibility of fingerprint evidence (pp. 1-6); explains that jurors tend to perceive fingerprint evidence as infallible and over-rely on it (pp. 6-7); and discusses the effectiveness of jury instructions in countering this preconception of infallibility (pp. 7-15). The motion describes, links to, and argues for a short informational video that research shows enables jurors to evaluate fingerprint evidence properly (pp. 8-10). It also argues for a reason-based jury instruction with specific factors for jurors to consider when deciding how much weight to give fingerprint testimony (pp. 12-19).

This motion challenges the scientific reliability of a prosecution expert’s testimony related to AHT/SBS. The motion outlines the history of AHT/SBS (pp. 11-15), details why AHT/SBS is not a scientifically reliable diagnosis, and applies the Daubert and Federal Advisory Committee Notes factors to AHT/SBS (pp. 29-33). The motion details how biomechanics undermine the premise of AHT/SBS (pp. 16-20), points to studies that demonstrate that children can in fact die from short accidental falls (pp. 19-20), and explains how the triad used to diagnose AHT/SBS can have non-abusive causes (pp. 21-26).

This motion relies on the Federal Rules of Evidence to argue for exclusion of expert DNA testimony about the likelihood ratio obtained using STRMix probabilistic genotyping software. Pages 5-8 describe the basic steps of DNA extraction and analysis. Pages 8-9 discuss the problems of trace DNA and the possibility of innocent transfer of DNA.  Page 11 explains how DNA analysis is less reliable when there is a complex DNA mixture and pages 12-15 discuss the danger that jurors will misunderstand (and prosecutors will misrepresent) what a likelihood ratio actually means.

This motion relies on the Federal Rules of Evidence to argue for exclusion of police testimony about the behavior of drug traffickers. Pages 13-14 rely on social science to argue that users of fentanyl, methamphetamine, and cocaine consume large quantities of each of those drugs daily to support their habit such that courts cannot infer distribution from larger amounts. Pages 15-16 collect national data to refute the suggestion that drug traffickers typically possess firearms.

This brief argues that law enforcement’s warrantless upload of a suspect’s SNP profile to GEDmatch and subsequent genealogical investigation violated the Alaska and federal constitutions. The brief explains how SNP-based genetic genealogy reveals highly information-rich data—including intimate familial associations and biological characteristics—far beyond traditional STR identity testing. It contends that both the suspect and his relatives retain a reasonable expectation of privacy in their shared genetic segments and that the third-party doctrine does not permit unregulated access to such sensitive data. Relying on Katz, Carpenter, and Alaska’s broader constitutional privacy protections, the brief argues that this novel surveillance technique constitutes a search requiring a warrant.

This brief explains why expert testimony on firearm and toolmark (FA/TM) identification should be excluded. FA/TM identification is premised on the unproven assumption that each firearm leaves unique, accidental, and individualized markings on spent ammunition despite evidence from several studies that this analysis lacks sound estimates of error rates, is characterized as subjective pathological science, and is not based on reliable scientific principles. This brief collects empirical studies and evidence demonstrating that FA/TM identification lacks scientific validity (pp. 14-22), and it explains the methodological problems and high error rates associated with various studies used to attempt to validate FA/TM identification (pp. 22-43). Because of the imprecise and problematic nature of FA/TM identification, the brief also contends that experts should not be allowed to testify about characteristics of spent ammunition that imply a match (pp. 49-59).

This motion relies on social science demonstrating the unreliability of witness attempts to identify people from surveillance videos/photographs and argues that due process and the evidence rules (Rules 602, 701, and 403) require exclusion of a police officer’s attempt to identify the defendant from a surveillance video.

Pages 2-4:  Discuss studies showing that humans are bad at matching people to images in photos/videos

Pages 4 –9:  Discuss studies showing that image quality (resolution, distance from subject, and moving versus still images), camera angle and viewpoint, lighting conditions at the time of the video or image capture, the presence or absence of obstructions to the camera’s view, and the size of the image captured all affect reliability

Pages 9 – 13: Discuss how situational factors including a lack of prior familiarity, cross-racial identification problems, and time delays between a prior exposure and the viewing of a surveillance photo/video all contribute to mistaken non-eyewitness identifications

Pages 15-16 – Discuss how these studies could also be used to (a) limit or prevent the prosecution from asking the judge/jury to compare a surveillance video/photo to the defendant, (b) obtain favorable expert testimony about the problems of non-eyewitness identification; (c) get the court to take judicial notice of these problems; (d) obtain favorable jury instructions about the problems with non-eyewitness identification testimony; (e) cross-examine non-eyewitnesses more effectively.

p. 40-86 outline the flaws in firearm identification, the current state of the field, and issues of cognitive bias

Pg. 13 – noting that there is no reliable scientific study validating the hypothesis that shaking alone can cause bleeding in the brain and eyes and neurological impairment; accidents can cause these symptoms

Pg. 14 – discussing thirty documented exonerations of innocent people wrongfully convicted based on shaken baby syndrome (and in 13% of those cases, the innocent person falsely confessed)

Pg. 19 – discussing a survey that reveals fewer than half of forensic pathologists think SBS is a valid diagnosis

Pgs. 20-28 – discussing why experts in biomechanical engineering are relevant to and regularly testify in SBS/AHT cases and how biomechanical studies show that shaking alone cannot produce the medical findings associated with SBS/AHT

Pgs. 28-31 – discussing the many non-abusive causes/circumstances that can present the same diagnostic signs relied upon to support SBS/AHT

Pgs. 38- 39 – collecting research that discusses the biasing impact of false confessions, how they corrode evidence collection and create a false appearance of corroboration, and how likely they are to lead to erroneous convictions

Pgs. 39-40 – documenting the problem of contaminated confessions

Pgs. 41-42 – discussing research showing that (a) individuals who have experienced trauma as well as (b) individuals who are depressed are more susceptible to police coercion and more likely to falsely confess

Pgs. 42-44 – discussing research about the dangers of police reliance on false evidence ploys to induce confessions

Pgs. 48-50 – surveying recent social science evidence on false confessions

Pgs. 50-53 – discussing social science research on confirmation biases in forensics

Explains the issue of secondary DNA transfer – footnotes on p. 7 specifically cite studies demonstrating a person’s DNA can be transferred to an object they never touched via an intermediate person or object.

This brief follows an extensive Frye hearing on bullet matching evidence and incorporates extensive criticism from the scientific community, an explanation of the unintended impact that a narrow definition of the “relevant scientific community” can have, and evidence of the ways that cognitive bias impermissibly taint pattern-matching evidence.

p. 35-65 detail research demonstrating bite-mark comparison has “no empirical support” high error rates, and is not accepted within the scientific community

This motion relies on federal rules of evidence and Daubert to argue that a physician should not be permitted to testify that a person died from an oxycodone overdose when there are alternative potential causes of death – such as cardiac arrhythmia – that have not be properly eliminated. More generally, the motion explains when doctors who rely on differential diagnosis – the process of identifying the cause of a medical problem by eliminating likely causes until the most probable one is isolated – are conducting a reliable, medical analysis versus when their analyses are compromised by cognitive biases. The social science collected in this motion would be useful to defenders challenging the validity of any causal conclusion physicians reach.

Pages 4-6 explain the differential diagnosis process and how it can lead physicians to make unreliable conclusions about cause of death.  Pages 6-17 discuss how cognitive biases like confirmation bias, role effects, the availability heuristic, and the representativeness error can infect differential diagnoses.  Pages 17-20 talk about when differential diagnoses are unreliable due to a physician’s failure to properly rule in certain causes and rule out potential alternatives.  Pages 20-24 draw analogies to the forensic sciences and argue that the physician in this case could testify that there was oxycodone in the patient’s system but should not have been able to opine with certainty that it caused the patient’s death.  Pages 24-28 explain why the doctor’s ultimate opinion invaded the province of and was unhelpful to the jury.

Pages 1-4 discuss the history and development of the DRE program; pages 6-10 explain how the DRE test fails Rule of Evidence 702 because it does not assist the trier of fact to understand a fact in issue and the officers who testify about it are not qualified in the relevant field of knowledge; and pages 11-26 explain why the DRE protocol fails each of the five Daubert factors.

P. 21-25 of the brief details the developments in scientific understanding of fire, including the 2004 National Fire Protection Association’s Guide for Fire and Explosion Investigations (NFPA 921), studies conducted by ATF and the National Institute of Justice, and other experts.

p. 22-33 explain the changing landscape of arson investigations and wide-scale rejection of the “negative corpus” theory that some fire investigations rely upon.

This document was filed in support of a motion to compel discovery of the underlying source code, parameters, error rates, input data, results, reports, analyst, and confidence scores of the Facial Recognition program used in a criminal case. The expert explains the steps involved in a facial recognition search and areas where subjective human decisions — and cognitive bias — are likely to impact the outcome of the search.

Filed by the Center for Integrity in Forensic Science, this brief explains the research demonstrating that cognitive bias in forensic analysts contributes to unreliable conclusions.

Focusing on retinal hemorrhages, this motion cites research showing no proven correlation between shaking and retinal hemorrhage, as well as studies documenting other (non-shaking) causes of retinal hemorrhage.

Civil rights complaint about problems with facial recognition technology – pgs. 9-12 collect research about errors with when images are of low quality, angles are different, resolution is bad; pgs. 12-15 collect research showing facial recognition algorithms are racially biased; pgs. 15-16 collect data about jurisdictions that have banned use of facial recognition technology because of its flaws

Amicus brief from the Innocence Project explains genotyping software, similar software programs used in courts that were shown to be unreliable, and why defense access to the software source code is necessary.

This amicus brief from the Legal Aid Society explains how probabilistic genotyping software works, why it’s unreliable, and why the defense has to be granted access to the software’s source code to present a full defense

Filed by the Innocence Project, this brief details research demonstrating that hair microscopy evidence does not meet the standards of reliable scientific evidence, as well as research showing how persuasive forensic testimony is to juries.

Based on forensic reports on latent fingerprint matching, this motion argues that fingerprint analysts can only accurately testify in terms of exclusion, rather than that two prints are a “match,” from a “common source,” or that any individual is “the source” of a latent fingerprint.

This brief challenges a police officer’s testimony opining that a shooter pictured in surveillance footage and the defendant were the same height.  The officer based his opinion on his visual observation of surveillance footage and measurements of the height of markings in the store. The Florida appellate court agreed that this was impermissible lay opinion testimony that invaded the province of the jury and required specialized expertise (https://caselaw.findlaw.com/court/fl-district-court-of-appeal/2076011.html).

Pages 17 – 23:  Discuss the science of photogrammetry – the process of discerning the size of objects in a photograph – and explain how estimates of an individual’s height in a photograph or video require expert calculations based on geometry, physics, and photogrammetric triangulation.  As a result, the brief argues that only a qualified expert can opine about the height of an individual in a photo or video, and a police officer’s opinion based on visual observation of the photos/video is unreliable, untethered from science, and inadmissible under both due process and evidentiary rules.

Testimony of defense expert on issues surrounding Shaken Baby Syndrome diagnoses

Summarizes research on accuracy of “criminal profiling” evidence over forty years, concluding profilers are no “better than bartenders at predicting the traits and features of offenders.” Also provides an overview of cases nationwide excluding criminal profiling evidence and finding that its major premise is faulty and essentially propensity evidence.

Argues that “likelihood ratio” evidence — the statistical frequency of a suspect’s characteristic — has not been sufficiently validated and is misleading to the jury because the jury conflates it with probability of guilt.

p. 36 – 94 contain testimony about shortcomings of latent print identification

Details the flaws in Bloodstain Pattern Analysis, the lack of enforced standards, and the high error rate. Additionally explains the danger of contextual bias impacting the decision of forensic analysts.

p. 11-15 overview reliability issues with fire investigations, particularly the lack of measurable standards and verifiable data.

Argues that gunshot residue evidence is not reliable

Explains process of latent fingerprint analysis, lack of uniform standards, false claims of “absolute certainty,” and why fingerprint analysis fails the Daubert standard.

Explains history of the ACE-V method, the risk of confirmation bias, and the lack of uniform standards in fingerprint matching.

Overviews shortcomings in firearm/toolmark analysis, specifically argues against any testimony of a “match”