Mississippi High Court Takes the Bite Out of Forensic Evidence

The Supreme Court’s 1993 decision in Daubert changed the thrust of Federal Rule of Evidence 702, which governs the admissibility of expert witness opinion testimony in both civil and criminal cases. Before Daubert, lawyers who hoped to exclude opinions lacking in evidentiary and analytical support turned to the Frye decision on “general acceptance.” Frye, however, was an outdated rule that was rarely applied outside the context of devices. Furthermore, the meaning and application of Frye were unclear. Confusion reigned on whether expert witnesses could survive Frye challenges simply by adverting to their claimed use of a generally accepted science, such as epidemiology, even though their implementation of epidemiologic science was sloppy, incoherent, and invalid.

Daubert noted that Rule 702 should be interpreted in the light of the “liberal” goals of the Federal Rules of Evidence. Some observers rejoiced at the invocation of “liberal” values, but history of the last 25 years has shown that they really yearned for libertine interpretations of the rules. Liberal, of course, never meant “anything goes.” It is unclear why “liberal” cannot mean restricting evidence not likely to advance the truth-finding function of trials.

Criminal versus Civil

Back on April 27, 2009, then President Barack Obama announced the formation of the President’s Council of Advisors on Science and Technology (PCAST). The mission of PCAST was to advise the President and his administration on science and technology, and their policy implications. Although the PCAST was a new council, presidents have had scientific advisors and advisory committees back to Franklin Roosevelt, in 1933.

On September 20, 2016, PCAST issued an important report to President Obama, Report to the President on Forensic Science in Criminal Courts: Ensuring Scientific Validity of Feature-Comparison Methods. Few areas of forensic “science,” beyond DNA matching, escaped the Council’s withering criticism. Bite-mark evidence in particular received a thorough mastication.

The criticism was hardly new. Seven years earlier, the National Academies of Science issued an indictment that forensic scientists had largely failed to establish the validity of their techniques and conclusions, and that the judiciary had “been utterly ineffective in addressing this problem.”1

The response from Obama’s Department of Justice, led by Loretta Lynch, was underwhelming.2 The Trump response was equally disappointing.3 The Left and the Right appear to agree that science is dispensable when it becomes politically inconvenient. It is a common place in the community of evidence scholars that Rule 702 is not applied with the same enthusiasm in criminal cases, to the benefit of criminal defendants, as the rule is sometimes, sporadically and inconsistently applied in civil cases. The Daubert revolution has failed the criminal justice system perhaps because courts are unwilling to lift the veil on forensic evidence, for fear they may not like what the find.4

A Grudging Look at the Scientific Invalidity of Bite Mark Evidence

Sherwood Brown was convicted of a triple murder in large measure as a result of testimony from Dr. Michael West, a forensic odontologist. West, as well as another odontologist, opined that a cut on Brown’s wrist matched the shape of a victim’s mouth. DNA testing authorized after the conviction, however, rendered West’s opinions edentulous. Samples from inside the female victim’s mouth yielded male DNA, but not that of Mr. Brown.5

Did the PCAST report leave an impression upon the highest court of Mississippi? The Supreme Court of Mississippi vacated Brown’s conviction and remanded for a new trial, in an opinion that a bitemark expert might describe as reading like a bite into a lemon. Brown v. State, No. 2017 DR 00206 SCT, Slip op. (Miss. Sup. Ct. Oct. 26, 2017). The majority could not bring themselves to comment upon the Dr. West’s toothless opinions. Three justices would have kicked the can down to the trial judge by voting to grant a new hearing without vacating Brown’s convictions. The decision seems mostly predicated on the strength of the DNA evidence, rather than the invalidity of the bite mark evidence. Mr. Brown will probably be vindicated, but bite mark evidence will continue to mislead juries, with judicial imprimatur.


1 National Research Council, Committee on Identifying the Needs of the Forensic Sciences Community, Strengthening Forensic Science in the United States: A Path Forward 53 (2009).

2 See Jordan Smith, “FBI and DoJ Vow to Continue Using Junk Science Rejected by White House Report,” The Intercept (Sept. 23, 2016); Radley Balko, “When Obama wouldn’t fight for science,” Wash. Post (Jan. 4, 2017).

3 See Radley Balko, “Jeff Sessions wants to keep forensics in the Dark Ages,” Wash. Post (April 11, 2017); Jessica Gabel Cino, “Session’s Assault on Forensic Science Will Lead to More Unsafe Convictions,” Newsweek (April 20, 2017).

4 See, e.g., Paul C. Giannelli, “Forensic Science: Daubert’s Failure,” Case Western Reserve L. Rev. (2017) (“in press”).