Document Category: Evidence

This motion argues that evidence of a client’s alleged substance use must be excluded because it constitutes impermissible character evidence under FRE 404(a), poses a high risk of unfair prejudice under FRE 403, and invites unqualified medical opinion testimony in violation of FRE 701. Citing social-science research showing that jurors associate substance use with immorality, violence, and dishonesty, the motion argues that such evidence leads jurors to condemn defendants based on stigma rather than proof of guilt, rendering the evidence unfairly prejudicial. Finally, it explains that terms such as “addict,” “dependence,” and “abuse” describe medical diagnoses that only qualified experts may offer, rendering lay testimony about addiction inadmissible.

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.

Relying on empirical studies from New York City, Chicago, Houston, and Dayton, Ohio, this motion explains that ShotSpotter alerts are unreliable because they rarely lead to discovery of gun-related crime or weapon use. It further argues that ShotSpotter alerts are unparticularized because they improperly equate assessments about a place with assessments about individuals in that place. Finally,  it contends that police should not be permitted to combine a ShotSpotter alert with other vague and unparticularized hunches—like the high-crime-area label—to establish reasonable suspicion, particularly given cited research about how ShotSpotter sensors are predominantly placed in communities of color and police are more likely to describe these same communities as high-crime areas regardless of actual crime rates.

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 argues that, in cases where the government must prove a prior conviction as an element of the offense, the trial should be bifurcated into two phases. In the first phase, the jury should hear evidence about the non-prior-conviction elements. Only if the jury returns a guilty verdict on these elements should the government be allowed to present evidence on the prior-conviction element. The motion relies on social science research demonstrating that (a) juries make propensity-based inferences when they learn about a defendant’s prior conviction; (b) these propensity-based conclusions are stronger in cases involving Black defendants due to implicit biases; and (c) limiting instructions do not effectively stop jurors from engaging in improper propensity-based reasoning. Because the prior conviction has no probative value with respect to the non-prior-conviction elements and bifurcation provides an easy way to remove the danger of unfair prejudice without compromising the prosecution’s need for the evidence on the prior-conviction element, the motion asks the court to join others around the country and split the guilt-phase of the trial into two different segments.

This motion challenges a forensic child abuse investigator’s attempt to bolster a child complainant’s credibility in a sexual assault case through testimony about Child Sexual Abuse Accommodation Syndrome (CSAAS). Drawing on social science and precedent, the motion argues that CSAAS testimony is not admissible under FRE 702 & Daubert because it is not scientifically reliable (pp. 15-19), has not been tested or subjected to peer review (pp. 19-24), and is not generally accepted (pp. 24-27). The danger of unfair prejudice also substantially outweighs any probative value such that it is inadmissible under FRE 403 (pp. 35-38), and CSAAS testimony is not helpful and improperly invades the jury’s province to determine witness credibility (pp. 38-40). The motion applies to testimony by a forensic examiner about alleged common responses of child sexual assault victims to abuse, including secrecy, helplessness, accommodation, delayed disclosure, and recantation (pp. 32-33).

This draft motion argues that physically distancing defendants from juries threatens the right to a fair trial by prejudicing jurors. Social science research suggests that physical distance subconsciously signals danger and threat [p. 1-2], and creates emotional distance that impedes interpersonal connection and understanding [p. 2-4]. Because there is no essential state reason for locating the prosecution at the table closer to the jury and there is substantial danger that distancing the defendant from the jury could unfairly prejudice him, this motion argues that both the rules of evidence and the defendant’s right to a fair trial with an impartial jury argue in favor of permitting the defense to sit at the table closer to the jury.  In cases where proximity to the jury would better serve a client’s interests, defenders can use this template to make such an argument informally to the court personnel or formally through motion practice.

This draft motion should be used to exclude a confession when police officers contaminate the confession by feeding nonpublic facts about the offense to the questioned suspect. Relying on social science research and police interrogation manuals, the motion argues that: (a) police-contaminated confessions are impermissibly coercive and result in involuntary statements (pg. 1-3); and (b) police-contaminated confessions should be excluded under Rule of Evidence 403 because their probative value is substantially outweighed by the danger of unfair prejudice (pg. 3-8).

This draft motion should be used to combat a probable cause finding predicated on a dog sniff if there is any indication that the dog’s handler prompted the dog (intentionally or unintentionally) to alert through a head nod, verbal command, repeated searches, etc. The motion relies on social science research about how readily dogs respond to subtle handler prompts.

This motion argues for the exclusion of opinion testimony by medical examiners on the manner of death in a homicide trial under both the rules of evidence and the Sixth Amendment jury trial right. It explains that medical examiners speculate as to the “manner” of death based on extraneous information provided to them, notes that these determinations are not based on science, and emphasizes that there is “no standardized or validated system” for making these judgments (pages 18-23). The motion also cites cognitive science in support of the claim that biases, including racial biases, can shape these “manner of death” determinations (pages 23-24). Attached to the motion are (1) transcripts of interviews with two medical examiners, exposing the problems with manner of death determinations; (2) an expert report and law review article detailing the cognitive science problems with these determinations; (3) the non-scientific manual used to instruct medical examiners on how to make these determinations; and (4) a letter signed by 86 forensic pathologists and death investigators about judicial misuse of manner of death determinations.

This draft section of a motion to suppress involuntary statements should be used when the government argues an offensive police interrogation tactic did not “cause” a Black male client’s confession because the client either did not appear outwardly affected/emotional when the tactic was used or responded with aggressive or callous behavior. To support the argument that such causation analyses are improper, it cites social science explaining that Black men are socialized to present as indifferent or even overly-aggressive when they are afraid and also explains that non-Black system actors are typically unable to correctly interpret Black people’s reactions.

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 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 ten-page sample motion argues that judges should not consider a client’s record of prior police contacts, including arrests, that did not result in criminal convictions for purposes of sentencing because such records are (1) inherently unreliable/ambiguous and (2) likely to exacerbate existing racial disparities in the criminal legal system. The motion draws on national data and jurisdiction-specific case studies to show that people of color, particularly Black Americans, are stopped, searched, arrested, and charged at disproportionately high rates, not because of higher rates of crime commission but because of implicit bias in law enforcement. This sample motion also uses local data from Washtenaw County, Michigan, that defenders should replace with their own jurisdiction’s data when available, to demonstrate that these national trends are reflected in the defendant’s jurisdiction as well.  Data from this motion could also be useful to defenders drafting 4th Amendment suppression motions or making evidentiary arguments at trial to exclude evidence of prior police contacts.  To the extent that the court or the prosecutor bring up prior police contacts at pre-trial release hearings, this data could also be useful to argue for exclusion of prior contacts during bail/pretrial release assessments.

This amicus brief argues that the State and lower courts relied upon irrelevant, unfairly prejudicial evidence (i.e. internet search history regarding abortion, abstention from prenatal care) to “articulate a motive for a murderous act on a newborn child.” The brief discusses the unfair prejudice that flows from admission of this evidence given stereotypes about women and motherhood (pages 5-6).  It also highlights empirical research showing that abstention from prenatal care can stem from “maternity care deserts” and “limited maternity care access,” rather than “murderous” intent (pages 6-7).

This sample motion relies on social science showing that the “sex offender” label evokes strong negative emotional responses to argue that Rule 403 should prohibit all references to a client as a “sex offender.” The motion also discusses alternative labels that are less likely to evoke prejudicial responses.

This is a draft motion defenders can use to seek exclusion under Rule 403 of a co-defendant’s redacted confession that directly or indirectly incriminates your client. This motion can be used even when exclusion under the Confrontation Clause fails post-Samia (the Supreme Court’s 2023 Confrontation Clause). This motion distinguishes between the Confrontation Clause and the Federal Rules of Evidence and explains why a separate Rule 403 analysis is necessary even if the court finds no Confrontation problem (pages 8-11). It describes social science research demonstrating that (a) juries are unlikely to follow the limiting instruction to consider the co-defendant’s statement only against the co-defendant (pages 4-7) and (b) secondary confessions by a co-defendant will be weighed heavily by juries even when the co-defendant has a motive to lie or downplay their role (pages 7-8). Taken together, this research shows that the likelihood of unfair prejudice is extremely high and outweighs any interest the system may have in a joint trial, requiring either severance of the trials or exclusion of the co-defendant’s redacted confession under Rule 403.

In this amicus brief, the ACLU of Iowa relies on social science to point out that juries are likely to (a) form negative impressions of criminal defendants who are associated with rap music, (b) view rap lyrics are more truthful and literal than lyrics from other musical genres; and (c) associate those who write or perform rap lyrics with criminality and bad character.  Pages 16-32 discuss why singing along to rap music is not typically probative in a criminal case, because fictional violent imagery is prevalent throughout popular culture and media, including in hip hop and rap music, but it is a form of artistic expression rather than journalism or autobiography.  Pages 35-37 collect social science research showing the danger of unfair prejudice by noting that jurors are more likely to form negative impressions of defendants as involved in general criminal activity when defendants are associated with rap music. And pages 26-27 discuss the problematic racial justice implications of such findings given that hip hop and rap are associated with Black people and Black culture.

This brief challenges Washington Evidence Rule 609 under the Washington State Constitution and objects to the introduction of a prior robbery conviction for impeachment purposes. The brief cites research showing that the admission of prior convictions against criminal defendants has minimal, if any, probative value on the defendant’s truthfulness as a witness, and instead lowers the prosecutor’s burden because of high risk of prejudice (p. 3-7). The brief explains that the categorization of robbery as a crime of dishonesty comes from antiquated honor norms rather than social science (p. 7-9). The brief also discusses the disproportionate impact of impeachment with prior convictions on defendants of color (p. 13-16).

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.

Draft motion arguing that finding many grams of methamphetamines does not necessarily support a conviction for possession with intent to distribute. Bottom of p. 1 through p. 3 explains that people addicted to methamphetamines use more frequently and in higher dosages than first-time users, using as much as one gram per day and rarely (but at least once) up to 15g in one day. Thus a person found with many grams of meth may only be a user rather than a dealer.  This data could also be used in other arguments, including: (1) a suppression argument that there is no probable cause to search a location for evidence of distribution when the quantity recovered or known about only suggests personal use; (2) a Rule of Evidence 403 argument limiting the testimony of a witness who wants to characterize a given quantity of meth as “a lot of drugs” or who wants to describe the client as a drug dealer or distributor; (3) a sentencing argument that a client is not as much of a danger to their community as someone actively selling drugs, despite the amount of drugs found.

The ACLU of Michigan included these reports as exhibits in its recent litigation attacking the constitutionality of Michigan’s Sex Offenders Registration Act (SORA). Does v. Whitmer (Does III), No. 22-cv-10209 (E.D. Mich.). The research cited in these reports — specifically on the low risk of recidivism among people convicted of sexual offenses and the counterproductive impact of registration/notification requirements on public safety and recidivism — could be used (1) when negotiating with a prosecutor for a plea to a non-registration offense, (2) when justifying such a plea to a sentencing judge, (3) in pre-trial release arguments, (4) in sentencing arguments where clients will be forced to register to show the onerous nature of registration, or (5) to support a motion in limine to preclude reference to a client as a “sex offender.”

(Note that the following page numbers are keyed to the page numbers in each expert report, which you can find in the middle bottom footer of each report):

Letourneau Report

Pages 2-11: Explaining through a dozen different scientific studies that sex offender registration and notification laws fail to increase community safety, do not have a general deterrent effect, and may even increase the incidence of crime by making it difficult for ex-offenders to find and maintain housing, employment, and social relationships.

Pages 11-12: Noting that researchers have found no connection between juvenile registration/notification and an increase in public safety but they have found increased incidences of attempted suicide among juvenile registrants as well as an increase in their likelihood of being victims of sexual assault themselves.

Pages 12-13: Citing research showing that 80% to 90% of adult males convicted of sex offenses are never reconvicted of a new sexual crime, including studies that debunk recidivism myths by showing rates of recidivism as low as 2-5%.

Pages 13-14: Discussing research showing that conviction offense has no bearing on recidivism risk.

Pages 16-17: Citing research showing the negative impact of registration on people’s mental health and ability to find and maintain stable housing, employment, and prosocial relationships, creating barriers for reintegration.

Pages 17-20: Discussing why the costs of implementing sex offender registration and notification laws are greater than any savings or benefits generated by those laws

Pages 21-22: Finding no correlation between failure-to-register violations and sexual recidivism

Socia Report

Pages 4-8:  Citing research showing that 90-95% of all sex crime arrests are for first-time offenders; the vast majority of sex crimes are not committed by strangers; and sex offender registration and notification laws do not reduce recidivism or make communities safer

Page 9-12:  Debunking through scientific research any suggestion that there is a high sexual recidivism rate and noting that sexual recidivism rates are actually lower than those of any other offense except murder

Pages 16-17:  Noting that language matters to public perceptions and that individuals are more likely to think negatively about someone described as a “sex offender” than someone described as an “individual convicted of crimes of a sexual nature” (this research might support a motion in limine about how clients should be described in court)

Pages 19-22:  Documenting how individuals on the sex offender registry are stigmatized in ways that affect reintegration including compromising employment and housing opportunities, as well as social support networks

Pages 22-25:  Noting that there is no consistent evidence that failure-to-register convictions predict increased sexual recidivism.

This brief argues that, contrary to stereotypes, drug use alone—even frequent or illicit use—does not necessarily indicate substance abuse (pp. 23, 28-29). Only a minority of users develop a diagnosable SUD (p. 23). A single positive drug test is insufficient to establish a SUD (p. 29). And equating substance use, even a SUD, with substantial risk of harm to a child is unsupported by the medical evidence (pp. 40-42).  Defenders can use the research collected in this brief to file motions in limine to exclude evidence of or arguments about substance use as more prejudicial than probative or to obtain expert testimony on substance use.  The research could also be useful at the pretrial release and sentencing stages to suggest that clients do not suffer from a substance abuse disorder and do not pose a danger.

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.

Pgs. 7-8 – summarize scientific research describing how people create entirely false memories, a study of false memory creation, and a list of false memory risk factors, particularly for children.

Pgs. 9-10 – explain how interview techniques can create false memories in children, even false memories that do not seem to directly relate to the questions asked by the interviewer, and why expert testimony is needed to educate the jury on the counterintuitive nature of memory creation (i.e., the more detailed a memory, the higher the likelihood of error).

Pgs. 12-14 argue that, because the science behind false memories is similar to that of mistaken eyewitness identifications and both require jury education to evaluate witness credibility, expert testimony on false memories should be admitted at the discretion of the trial judge under the same logic.

p. 13-59 overview studies of Shotspotter accuracy and racially biased implementation

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.

Details the dilemma that admitting a prior felony conviction results in: if the defendant testifies and his conviction is introduced, research shows there is a heightened risk that the jury will use the prior conviction to “draw an impermissible inference.” However, if the defendant chooses not to testify in order to prevent his conviction from being introduced, research shows people are more likely to find him guilty because he did not testify.

p. 18 – 23 incorporate research about the high susceptibility of adolescents to persuasion, especially by police. Amici argues that this makes adolescents more likely than adults to give false information to authority figures. Includes research on how adolescents respond to authority under stress.

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

Overview of flaws in proposed testimony explaining how children respond in aftermath of sexual abuse

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

This expert report collects and describes cutting edge social science describing the problems with eyewitness identifications including: the effects of poor lighting and distance (p. 5); the effects of a quick exposure and the problem of witnesses’ overestimating the length of exposure (p. 5-6); problems with cross-racial identifications (p. 6); problem if witness previously viewed the person in another context (unconscious transference) (p. 7); problem of memory loss over time (p. 7); suggestive instructions & failure to warn that culprit may not be in line up (p. 8); problems with nonblind lineup administration (pp. 8-9); problems with biased lineup composition (bad fillers) (p. 9); what can be learned from how long it takes witness to make ID (p. 10); problems with in court identifications (commitment effect and inherent suggestiveness) (pp. 10-11); problems with witnesses being overconfident about IDs (pp. 11-12)

Details risk factors for false confessions, benefits of a defense expert on false confessions, and why expert testimony on false confessions satisfies Daubert

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.

“When jurors are presented with evidence that is particularly gruesome, they are likely to experience a visceral emotionally charged feeling that leads them to be inappropriately punitive.” Incorporates studies demonstrating that exposure to gruesome evidence decreases the brain’s capacity for logical reasoning.

p. 22-38 discuss the use of 404(b) “other acts” evidence and why evidence of drug possession is not relevant to intent to distribute drugs. The brief goes on to outline research demonstrating that such “other acts” evidence is highly likely to improperly prejudice the jury in a way that cannot be cured by a limiting instruction.

Argument that using in-court IDs as the only identification in case is a violation of the Due Process Clause because they create a substantial risk of misidentification. Social science studies cited throughout, specifically supporting reliability concerns (pgs. 10-12) and policy arguments (pgs. 13-15)

Transcript of testimony and argument pursuant to the defense motion to exclude the government’s expert witness. Defense witness explains (with research studies as examples) confirmation bias, contextual bias, and exposure to task-irrelevant information. Arguments: p. 57-70.

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.

Witness testifies about confirmation bias, clothing bias, witness degree of certainty, police witness accuracy, and face-to-photo ID accuracy

p. 14 – 22 outline research on how jurors respond to limiting instructions, demonstrating that “providing a limiting instruction likely has little effect because it is almost impossible for jurors to forget evidence for one purpose, while remembering it for another.”

p. 9-18 overview studies on unreliability of cross-racial identifications and juror tendency to overestimate eyewitness accuracy. Brief also details why expert testimony and cross-examination do not eliminate the need for a jury instruction.

Incorporates numerous studies demonstrating why show ups are unreliable

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

Brief outlines the factors that have been demonstrated to impact the reliability of eyewitness identification and argues for jury instructions that explain each individual factor.

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. 9-13 cite research on jury bias, impact of prior conviction evidence, and inefficacy of limiting instructions about prior convictions

Argues that showing a witness a photograph of the defendant prior to trial testimony shares the same unreliability as a show-up and is impermissibly suggestive.

p. 8 – 12 outline existing research on how jurors respond to and use evidence of prior convictions. Incorporates research demonstrating that limiting instructions do not cure the prejudice, as jurors still use prior convictions as propensity evidence even when instructed not to.

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

In-court identifications are inherently suggestive because they imply to the witness that the prosecutor has confirmed the witness’ initial identification. This brief argues that such an identification is more suggestive than a show-up and that the witness’ sense of accuracy artificially increases during subsequent identifications.

Because of the inherently suggestive nature of in-court identifications, courts should (1) subject them to the same protections and scrutiny as suggestive pretrial identification procedures (pgs. 4-9 of brief); (2) update existing standards and law to align with social science and other, more protective jurisdictions (pgs. 13-22 of brief); and (3) recognize that in-court identifications may be a violation of due process rights (pgs. 26-36 of brief)

Filed by the American Psychological Association, this brief supports specific jury instructions on eyewitness memory:

“Human memory is not foolproof. Research has revealed that human memory is not like a video recording that a witness need only replay to remember what happened. Memory is far more complex. The process of remembering consists of three stages: acquisition — the perception of the original event; retention — the period of time that passes between the event and the eventual recollection of a piece of information; and retrieval — the stage during which a person recalls stored information. At each of these stages, memory can be affected by a variety of factors.”

“Although nothing may appear more convincing than a witness’s categorical identification of a perpetrator, you must critically analyze such testimony. Such identifications, even if made in good faith, may be mistaken. Therefore, when analyzing such testimony, be advised that a witness’s level of confidence, standing alone, may not be an indication of the reliability of the identification.”

Affidavit submitted by proposed defense expert detailing the existing research on how juries perceive the testimony of jailhouse informants (otherwise called “secondary confessions.”)

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.

p. 7-12 collect lower court cases excluding gruesome photos due to likelihood they would inflame the jury.

p. 8-12 incorporate social science studies on how jurors respond to testimony designated as “expert”

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”