Evidence Commons^™

The Academy Standards Board For Firearms And Toolmarks, Robert M. Sanger

Robert M. Sanger

Ultracrepidarianism In Forensic Science: The Hair Evidence Debacle, David H. Kaye

David Kaye

For over 130 years, scientific sleuths have been inspecting hairs under microscopes. Late in 2012, the FBI, the Innocence Project, and the National Association of Criminal Defense Lawyers joined forces to review thousands of microscopic hair comparisons performed by FBI examiners over several of those decades. The results have been astounding. Based on the first few hundred cases in which hairs were said to match, it appears that examiners “exceeded the limits of science” in over 90% of their reports or testimony. The disclosure of this statistic has led to charges that the FBI “faked an entire field of forensic …

How Good Is Good Enough?: Expert Evidence Under Daubert And Kuhmo, David H. Kaye, David L. Faigman, Michael J. Saks, Joseph Sanders

David Kaye

This essay is a response to Professor Edward Imwinkelried's article, "Should the Courts Incorporate a Best Evidence Rule into the Standard Determining the Admissibility of Scientific Testimony?: Enough is Enough When it is not the Best." The authors have two basic points. First, the authors wish to make it clear that they never proposed the "best evidence rule" that he so vigorously attacks, and they think his suggestion that they did so is strained. Second, they wish to reiterate that courts sometimes should do more than they have to ensure that expert testimony is reasonably sound. The important debate underway …

Confronting Science: Expert Evidence And The Confrontation Clause, David H. Kaye, Jennifer L. Mnookin

David Kaye

In Crawford v Washington, the Supreme Court substantially changed its understanding of how the Confrontation Clause applies to hearsay evidence. Since then, the Court has issued three bitterly contested expert-evidence-related Confrontation Clause decisions, and each one has generated at least as many questions as answers. This article analyzes this trilogy of cases, especially the most recent, Williams v Illinois.

In Williams, the Court issued a bewildering array of opinions in which majority support for admitting the opinion of a DNA analyst about tests that she did not perform was awkwardly knitted together out of several incompatible doctrinal …

Amicus Brief: Kumho Tire V. Carmichael, Neil Vidmar, Richard Lempert, Shari Diamond, Valerie Hans, Stephan Landsman, Robert Maccoun, Joseph Sanders, Harmon Hosch, Saul Kassin, Marc Galanter, Theodore Eisenberg, Stephen Daniels, Edith Greene, Joanne Martin, Steven Penrod, James Richardson, Larry Heuer, Irwin Horowitz

Robert MacCoun

This brief addresses the issue of jury performance and jury responses to expert testimony. It reviews and summaries a substantial body of research evidence about jury behavior that has been produced over the past quarter century. The great weight of that evidence challenges the view that jurors abdicate their responsibilities as fact finders when faced with expert evidence or that they are pro-plaintiff, anti-defendant, and anti-business.

The Petitioners and amici on behalf of petitioners make a number of overlapping, but empirically unsupported, assertions about jury behavior in response to expert testimony, namely that juries are frequently incapable of critically evaluation …

Science On Trial, Valerie P. Hans

Valerie P. Hans

The increasing complexity of both criminal and civil jury trials raises a host of issues for lawyers and judges. For the litigator, the first question is whether a jury can be trusted with a case that turns on highly technical evidence. For the trial judge, there are decisions about the admissibility of expert testimony, whether it is based on sound science, and whether a jury is likely to be misled by scientific claims. Should the judge permit jury innovations such as note taking, question asking, and juror discussions of evidence during the trial, hoping to increase jury comprehension of the …

Can Jury Trial Innovations Improve Juror Understanding Of Dna Evidence?, B. Michael Dann, Valerie P. Hans, David H. Kaye

Valerie P. Hans

A single spot of blood on a pink windowsill will tell investigators who broke a windowpane, turned a lock, and kidnapped 2-year-old Molly Evans from her bedroom in the middle of the night. An expert witness will testify that the DNA profile of the blood evidence recovered from the windowsill was entered into CODIS, an electronic database of DNA profiles. That process yielded a “hit,” identifying the defendant as the most likely source of the blood inside Molly’s room. But will jurors be able to understand the expert’s intricate analysis and use it to reach a verdict? And what—if any—steps …

Testing Jury Reforms, Valerie P. Hans, B. Michael Dann, David H. Kaye, Erin J. Farley, Stephanie Albertson

Valerie P. Hans

DNA evidence has become a key law enforcement tool and is increasingly presented in criminal trials in Delaware and elsewhere. The integrity of the criminal trial process turns upon the jury's ability to understand DNA evidence and to evaluate properly the testimony of experts. How well do they do? Can we assist them in the process?

Statistics In The Jury Box: How Jurors Respond To Mitochondrial Dna Match Probabilities, David H. Kaye, Valerie P. Hans, B. Michael Dann, Erin J. Farley, Stephanie Albertson

Valerie P. Hans

This article describes parts of an unusually realistic experiment on the comprehension of expert testimony on mitochondrial DNA (mtDNA) sequencing in a criminal trial for robbery. Specifically, we examine how jurors who responded to summonses for jury duty evaluated portions of videotaped testimony involving probabilities and statistics. Although some jurors showed susceptibility to classic fallacies in interpreting conditional probabilities, the jurors as a whole were not overwhelmed by a 99.98% exclusion probability that the prosecution presented. Cognitive errors favoring the defense were more prevalent than ones favoring the prosecution. These findings lend scant support to the legal argument that mtDNA …

Judges, Juries, And Scientific Evidence, Valerie P. Hans

Valerie P. Hans

The rise in scientific evidence offered in American jury trials, along with court rulings thrusting judges into the business of assessing the soundness of scientific evidence, have produced challenges for judge and jury alike. Many judges have taken up the duty of becoming “amateur scientists.” But what about juries? Surely they too could benefit from assistance as they attempt to master and apply complex testimony about scientific matters during the course of a trial. Concerns about the jury’s ability to understand, critically evaluate, and employ scientific evidence in deciding complex trials have led to many suggestions for reform. This article …

Junk Philosophy Of Science?: The Paradox Of Expertise And Interdisciplinarity In Federal Courts, David S. Caudill, Richard E. Redding

David S Caudill

No abstract provided.

Speaking Science To Law, Deborah Hussey Freeland

Deborah M. Hussey Freeland

involving a strong scientific consensus, the powerful qualities of scientific knowledge are easily lost in translation. Moreover, even prominent scientists who are committed to providing accurate information to legal fact-finders may suffer reputational harm simply for participating in an adversarial process.

This article analyzes the connection between law and science through the expert witness from the perspectives of epistemology and cross-cultural communication, focusing on the distinct ways in which scientists and lawyers know, value and express their knowledge. When a lawyer meets with a scientific expert witness, more confusion attends their interaction than either likely realizes. Linguistic translation is necessary--but …