Evidence Commons^™

Ai Suppression: E-Discovery Software And Brady, Jason Hartline, Liren Shan, Alec Sun, Rebecca Wexler

Faculty Scholarship

Prosecutors regularly rely on AI e-discovery software, known as technology assisted review (TAR) tools, to sort and prioritize digital evidence. These tools implicate constitutional concerns: they can either risk suppressing or help to surface exculpatory and impeachment evidence that prosecutors must disclose under the Brady due process rule. Yet doctrine, agency guidance, and scholarship offer virtually no direction on their use.

This Article examines how TAR affects Brady compliance. Using computer science simulations on synthetic data sets, we show that TAR can either hide or help to expose Brady evidence, depending on how it is configured and the configurations of …

Metrics Not Thresholds: How To Regulate Ai And Other Expert Methods For Use In Criminal Investigations And Proceedings, Rebecca Wexler

Faculty Scholarship

Should regulators set performance thresholds for AI tools used in the criminal legal system? This Article draws on U.S. evidence law for guidance. Its answer is ... don’t. Instead of gatekeeping with ex ante performance thresholds, regulators should require or incentivize metrics of reliability that can be clearly communicated to end-user decisionmakers.

Childhood, Likelihood, And Probative Value: A Further Call For Greater Probity And Less Childism In Evidence Law, Mae C. Quinn

Faculty Scholarship

No abstract provided.

Evidence And Assessing Verbatim Transcription Quality Of Black English And Standard American English, L. Alexander Walker Iii

Faculty Scholarship

This chapter explores the accuracy of private transcription services when transcribing Black English and Standard American English. Courts and lawyers in the US regularly rely on transcripts from such services, but third-party verification of their accuracy, especially with respect to their quality when faced with nonstandard language varieties, is lacking. This study draws on experimental methods to contrast the quality of transcription services offered by transcribers and AI route. The quantitative results show that transcription by humans and AI resulted in more mistakes when transcribing Black English than when transcribing Standard American English. Furthermore, a qualitative analysis reveals that these …

Keeping Evidence Real, Anya Bernstein, Julia Simon-Kerr

Faculty Scholarship

Commentators largely agree that the Federal Rules of Evidence have problems. Expert testimony standards admit junk science. Impeachment rules chill defendant testimony. The hearsay regime defies consistent application and obstructs self-representation. The list goes on: Many rules fail to assist, or affirmatively thwart, jurors trying to make good decisions. Such shortcomings disproportionately harm those with the least power in the system, raising profound questions about whether the evidence code serves its statutory mandate—to promote truth and justice in court proceedings. In the face of widely recognized problems, the government body charged with managing the evidence code—the Advisory Committee on Evidence …

The Brady Materiality Standard, Brandon L. Garrett, Adam M. Gershowitz

Faculty Scholarship

The Brady doctrine requires prosecutors to disclose all favorable and material evidence to the defense. To effectuate that rule, the U.S. Supreme Court has defined materiality as a “reasonable probability” that the evidence would have affected the outcome at trial. But apart from that definition, the Court has resisted offering any further guidance to lower courts. While far too little is known about how Brady materiality claims are actually adjudicated, there is strong evidence that courts often reject Brady claims involving withheld evidence on the grounds that the evidence was not significant enough to be material.

To examine how Brady …

Judicial Enforcement Of Evidence Law, G. Alexander Nunn

Faculty Scholarship

The truth matters. At least it should. In the courtroom, truth can serve as the cornerstone of justice, liberating the innocent, vindicating victims, and holding the guilty to account. Indeed, truth is such a normative imperative that an entire legal discipline now focuses on fostering its discovery at trial—evidence law. By regulating both the reliability of proof and the rationality of cognitive inferences, evidence law seeks to help factfinders discern truth and reach an accurate verdict. And given the importance of that role, one might naturally assume that the strict enforcement of evidence law would be a legal mandate of …

New Insights On Expert Opinion About Eyewitness Memory Research, Travis M. Seale-Carlisle, Adele Quigley-Mcbride, Jennifer E. F. Teitcher, William E. Crozier, Chad S. Dodson, Brandon L. Garrett

Faculty Scholarship

Experimental psychologists investigating eyewitness memory have periodically gathered their thoughts on a variety of eyewitness memory phenomena. Courts and other stakeholders of eyewitness research rely on the expert opinions reflected in these surveys to make informed decisions. However, the last survey of this sort was published more than 20 years ago, and the science of eyewitness memory has developed since that time. Stakeholders need a current database of expert opinions to make informed decisions. In this article, we provide that update. We surveyed 76 scientists for their opinions on eyewitness memory phenomena. We compared these current expert opinions to expert …

Affording Oral Tradition Evidence Due Weight Before The International Court Of Justice, Terrence Neal

Faculty Scholarship

Oral traditions are irreplaceable sources of historical information, particularly with regard to Indigenous Peoples’ histories and cultures. However, when states have submitted oral traditions as evidence of historical practices, events, and circumstances in cases before the International Court of Justice (“Court”), the Court has been reluctant to afford them significant weight. This Article, which is the first detailed study on the Court’s treatment of oral traditions, examines whether the Court is failing to provide them due or appropriate weight. Based on historical, archaeological, and anthropological research, it establishes that oral traditions can be as reliable as written documents for reconstructing …

The Incoherence Of Evidence Law, G. Alexander Nunn

Faculty Scholarship

What is the purpose of evidence law? The answer might seem intuitive. Evidence law exists, of course, to foster verdict accuracy, legitimacy, and efficiency. But these kindred aims often come into conflict. Policy tradeoffs are inescapable in evidence law, meaning that an evidentiary regime must clarify how its normative objectives cohere. Do accuracy, legitimacy, and efficiency work together on equal footing, such that the goal of a code is to maximize each objective to the extent possible? Or does one of evidence law’s aims take precedence over the rest? And if one goal takes priority, what is the role of …

The Automated Fourth Amendment, Maneka Sinha

Faculty Scholarship

Courts routinely defer to police officer judgments in reasonable suspicion and probable cause determinations. Increasingly, though, police officers outsource these threshold judgments to new forms of technology that purport to predict and detect crime and identify those responsible. These policing technologies automate core police determinations about whether crime is occurring and who is responsible. Criminal procedure doctrine has failed to insist on some level of scrutiny of—or skepticism about—the reliability of this technology. Through an original study analyzing numerous state and federal court opinions, this Article exposes the implications of law enforcement’s reliance on these practices given the weighty interests …

Long Live The Federal Rules Of Evidence!, Daniel J. Capra, Liesa L. Richter

Faculty Scholarship

The Federal Rules of Evidence have been pronounced dead. Indeed, the Federal Rules of Evidence have recently been declared dormant, stagnant, frozen, lethargic, and yes, deceased. In The Living Rules of Evidence, 170 U. Pa. L. Rev. 937 (March 2022), Professor Alexander Nunn claims that the Rules are lifeless, incapable of any meaningful change, and littered with anachronistic and even dangerous standards and provisions. To blame for the moribund state of the Federal Rules of Evidence is the bureaucratic and complex federal rulemaking process that requires amendments to traverse multiple constituencies in a multi-year process before taking effect. As a …

Judging Firearms Evidence, Brandon L. Garrett, Eric Tucker, Nicholas Scurich

Faculty Scholarship

Firearms violence results in hundreds of thousands of criminal investigations each year. To try to identify a culprit, firearms examiners seek to link fired shell casings or bullets from crime scene evidence to a particular firearm. The underlying assumption is that firearms impart unique marks on bullets and cartridge cases, and that trained examiners can identify these marks to determine which were fired by the same gun. For over a hundred years, firearms examiners have testified that they can conclusively identify the source of a bullet or cartridge case. In recent years, however, research scientists have called into question the …

Deepfakes In Court: How Judges Can Proactively Manage Alleged Ai-Generated Material In National Security Cases, Abhishek Dalal, Chongyang Gao, Paul W. Grimm, Maura R. Grossman, Daniel W. Linna Jr., Chiara Pulice, V. S. Subrahmanian, John Tunheim

Faculty Scholarship

Dall-E. ChatGPT GPT-4. Words that did not exist in the English lexicon just a few years ago are now commonplace. With the widespread availability of Artificial Intelligence (AI) tools, specifically Generative AI, whether in the context of text, audio, video, imagery, or even combinations of these, it is inevitable that trials related to national security will involve evidentiary issues raised by Generative AI. We must confront two possibilities: first, that evidence presented is AI-generated and not real and, second, that other evidence is genuine but alleged to be fabricated. Technologies designed to detect AI-generated content have proven to be unreliable, …

False Accuracy In Criminal Trials: The Limits And Costs Of Cross Examination, Lisa Kern Griffin

Faculty Scholarship

According to the popular culture of criminal trials, skillful cross-examination can reveal the whole “truth” of what happened. In a climactic scene, defense counsel will expose a lying accuser, clear up the statements of a confused eyewitness, or surface the incentives and biases in testimony. Constitutional precedents, evidence theory, and trial procedures all reflect a similar aspiration—that cross-examination performs lie detection and thereby helps to produce accurate outcomes. Although conceptualized as a protection for defendants, cross-examination imposes some unexplored costs on them. Because it focuses on the physical presence of a witness, the current law of confrontation suggests that an …

The Brady Database, Brandon L. Garrett, Adam M. Gershowitz, Jennifer Teitcher

Faculty Scholarship

The Supreme Court’s landmark ruling in Brady v. Maryland turns sixty this year. The Brady doctrine, which requires the government to disclose favorable and material evidence to the defendant, is one of the most frequently litigated criminal procedure issues. Yet, despite decades of Brady cases in federal and state courts, we still know relatively little about how Brady claims are litigated, adjudicated, and what such claims can tell us about the criminal justice system writ large. Scholars are in the dark about how often Brady violations occur, whether it is primarily the fault of prosecutors or the police, whether violations …

Evidence Law’S Blind Spots, James Macleod

Faculty Scholarship

No abstract provided.

Models And Limits Of Federal Rule Of Evidence 609 Reform, Anna Roberts

Faculty Scholarship

No abstract provided.

Bending The Rules Of Evidence, Edward K. Cheng, G. Alexander Nunn, Julia Simon-Kerr

Faculty Scholarship

The evidence rules have well-established, standard textual meanings—meanings that evidence professors teach their law students every year. Yet, despite the rules’ clarity, courts misapply them across a wide array of cases: Judges allow past acts to bypass the propensity prohibition, squeeze hearsay into facially inapplicable exceptions, and poke holes in supposedly ironclad privileges. And that’s just the beginning.

The evidence literature sees these misapplications as mistakes by inept trial judges. This Article takes a very different view. These “mistakes” are often not mistakes at all, but rather instances in which courts are intentionally bending the rules of evidence. Codified evidentiary …

Environmental Evidence, Seema Kakade

Faculty Scholarship

The voices of impacted people are some of the most important when trying to make improvements to social justice in a variety of contexts, including, criminal policing, housing, and health care. After all, the people with on the ground experience know what is likely to truly effectuate change in their community, and what is not. Yet, such lived experience is also often significantly lacking and undermined in law and policy. People with lived experience tend to be seen as both community experts with valuable knowledge, as well as non-experts with little valuable knowledge. This Article explores the lived experience with …

Of Bass Notes And Base Rates: Avoiding Mistaken Inferences About Copying, Christopher Buccafusco, Rebecca Tushnet

Faculty Scholarship

To prove copyright infringement, a plaintiff must convince a jury that the defendant copied from the plaintiff’s work rather than independently creating it. To prove copying, especially cases involving music, it’s common for plaintiffs and their experts to argue that the similarities between the parties’ creative works are so great that it is simply implausible that the defendant’s work was created without copying from the plaintiff’s work. Unfortunately, in its present form, the argument is mathematically illiterate: It assumes, without any underlying evidence, that the experts know or could reasonably estimate how likely it is that a song with similarity …

Theorizing Corroboration, Maggie Wittlin

Faculty Scholarship

A child makes an out-of-court statement accusing an adult of abuse. That statement is important proof, but it also presents serious reliability concerns. When deciding whether it is sufficiently reliable to be admitted, should a court consider whether the child’s statement is corroborated—whether, for example, there is medical evidence of abuse? More broadly, should courts consider corroboration when deciding whether evidence is reliable enough to be admitted at trial? Judges, rule-makers, and scholars have taken significantly divergent approaches to this question and come to different conclusions.

This Article argues that there is a key problem with using corroboration to evaluate …

Life, Liberty, And Data Privacy: The Global Cloud, The Criminally Accused, And Executive Versus Judicial Compulsory Process Powers, Rebecca Wexler

Faculty Scholarship

U.S. policymakers’ responses to a wave of global data privacy laws are creating a deep structural unfairness in the criminal legal system. In an era of cloud computing, when data about communications and activities occurring anywhere in the world can be stored on servers located anywhere else, access to such data can make the difference between convictions and acquittals. At the same time, new global data privacy laws risk cutting off cross-border access to digital evidence in criminal investigations. Recognizing the threat to law enforcement interests, U.S. policymakers enacted the CLOUD Act of 2018 to create special procedures for law …

Ignorance Of The Rules Of Omission: An Essay On Privilege Law, Rebecca Wexler

Faculty Scholarship

Evidentiary privileges--that is, rules that empower people to withhold evidence from legal proceedings-are one thread in a mesh of secrecy powers that control the flow of information in society. They are part and parcel of the laws, rules, norms, and practicalities that determine who can conceal and who can compel, that allocate power based on access to knowledge and its opposite. Despite the significance of privileges and of the harms that they produce, our understanding of this body of law has profound gaps.5 The questions posed above turn out to be more challenging than they might at first appear. Notwithstanding …

Judging Firearms Evidence And The Rule 702 Amendments, Brandon Garrett, Nicholas Scurich, Eric Tucker, Hannah Bloom

Faculty Scholarship

No abstract provided.

Is Disclosure And Certification Of The Use Of Generative Ai Really Necessary?, Maura R. Grossman, Paul W. Grimm, Daniel G. Brown

Faculty Scholarship

No abstract provided.

Optimal Standards Of Proof In Antitrust, Murat C. Mungan, Joshua Wright

Faculty Scholarship

Economic analyses of antitrust institutions have thus far focused predominantly on optimal penalties and the design of substantive legal rules, and have largely ignored the standard of proof used in trials as a policy tool in shaping behavior. This neglected tool can play a unique role in the antitrust context, where a given firm may have the choice to engage in exceptional anticompetitive or procompetitive behavior, or simply follow more conventional business practices. The standard of proof used in determining the legality of a firm’s conduct affects not only whether the firm chooses to engage in pro- versus anticompetitive behavior, …

The Living Rules Of Evidence, G. Alexander Nunn

Faculty Scholarship

The jurisprudential evolution of evidence law is dead. At least, that’s what we’re expected to believe. Ushered in on the wings of a growing positivist movement, the enactment of the Federal Rules of Evidence purported to quell judicial authority over evidence law. Instead, committees, conferences, and members of Congress would regulate any change to our evidentiary regime, thereby capturing the evolution of evidence law in a single, transparent code.

The codification of evidence law, though, has proven problematic. The arrival of the Federal Rules of Evidence has given rise to a historically anomalous era of relative stagnation in the doctrinal …

Proving Copying, Shyamkrishna Balganesh, Peter S. Menell

Faculty Scholarship

Proof that a defendant actually copied from a copyrighted work is a critical part of a claim for copyright infringement. Indeed, absent such copying, there is no infringement. The most common method of proving copying involves the use of circumstantial evidence, consisting of proof that a defendant had “access” to the protected work, and a showing of “similarities” between the copy and the protected work. In inferring copying from the combination of such evidence, courts have for many decades developed a framework known as the “inverse ratio rule,” which allows them to modulate the level of proof needed on access …

The Law And Science Of Eyewitness Evidence, Thomas D. Albright, Brandon L. Garrett

Faculty Scholarship

Eyewitness evidence crucially depends on visual perception and memory, which are quite fallible. The potential inaccuracy of eyewitness memory has been long demonstrated in cases of wrongful conviction. Today, decades of scientific research on visual perception and memory have identified key causes of error and methods for improving eyewitness performance. Eyewitness evidence, where identification procedures themselves involve experiments, lends itself to scientific research as do few other areas in law. As a result, eyewitness evidence has become a testing ground for the use of science to inform the law. This Article examines how legal actors—state and federal courts, state lawmakers, …