George Zimmerman Trial: Ruling on Audio Experts’ Testimonies

george zimmerman trialOn June 25th, the George Zimmerman murder trial began, with both the prosecution and the defense making their opening statements, setting the stage for the rest of the trial.[1] During the previous weekend, however, Judge Debra Nelson ruled that the testimonies by the prosecution’s experts were inadmissible.[2] As we covered last week (Technology Expert Witnesses in the Trayvon Martin Case), the court discussed whether to admit testimony from two experts, Dr. Alan Reich and Mr. Thomas Owen, which positively identified the individual screaming on a 911 call as Trayvon Martin. In response, the defense called four experts, who discussed the difficulty of obtaining a positive identification based on the audio that was available to them. It should be noted, however, that while the question revolved around the testimony of the experts, the 911 call, itself, was admissible (and was played for the jury on the first day of the trial).

Citing the Frye test, and its realization in Ramirez v. State, [651 So. 2d 1164 (Fla. 1995)], Judge Nelson ruled that the essential component of the test found in Ramirez, as it pertained to the Zimmerman case, was whether the prosecution expert’s methodologies were based on a scientific principle or discovery that was, “sufficiently established to have gained general acceptance in the particular field it belongs.”[3] This is not strictly a measurement of what a majority of relevant practitioners believe, but rather the court should, “peruse disparate sources… and decide for itself whether the theory in issue had been ‘sufficiently test and accepted by the relevant scientific community.”[4]

With audio identification, there are three methodologies that are utilized by audio forensic engineers: auditory phonetic analysis, spectral or acoustic-phonetic analysis, and biometric analysis. The court reviewed the different methods, conclusions, and testimonies of the experts, and reached the conclusion that aural perception and spectral analysis had been sufficiently established, but biometric analysis was not “widely accepted at this time.”[5]

The court then sought to determine whether the application of technologies by the prosecution’s experts was sufficiently established to have gained general acceptance in the scientific community. The court noted that if a principle is, “untested and lacks indicia of acceptability, it was more likely to be ruled inadmissible.”[6] Also, having a personal (monetary) stake in a methodology indicated that the court should be more cautious of any conclusions. Overall, and this was the real issue with the prosecution’s experts, “The State did not offer any disinterested or impartial witness to establish that the scientific principles utilized by Mr. Owen and Dr. Reich testified in support of their own technologies and techniques…Although aural perception and spectral analysis are not new or novel, their application by the State’s witnesses to the samples from the 911 call in this case is a scientific technique that is new and novel.”[7] Because of this, Jude Nelson ruled that the Mr. Owen’s and Dr. Reich’s testimony was not admissible (including Dr. Reich’s testimony on specific words that he was able to make out on the 911 call).

In a footnote, the court acknowledged their transition to the Daubert standard (which should go into effect by July 1st), shifting the standard that the court will use to evaluate expert witnesses.[8] Still, as suggested before, this is a significant blow for the prosecution. Allowing testimony from a (albeit, limited) scientific authority would have lent credence to the idea that Zimmerman was not acting in self-defense. This was highlighted by the fact that, on the opening day of the trial, the 911 call played a prominent role, as it was played for the court .[9]

As with most cases, there are some illustrative points for future litigation. When new technology or a new application of an existing technology is being presented, it is critical that their methodology can be fully explained. In the Zimmerman case, it was not necessarily that the prosecution’s experts were using a new technology, but rather that they were using a methodology that was acknowledged by the court in a new way. Coupled with the fact that both experts were “interested” in their methodologies, the judge disallowed their conclusions. As the trial progresses, if the 911 call is featured as prominently as it was on the first day, the identity of the individual screaming on the call is likely to be revisited by the litigating parties.