Voice Expert Witness

Challenging Voice Experts in Trayvon Martin-Zimmerman case

Written on Thursday, May 16th, 2013 by Colin Holloway, Attorney at Law
Filed under: In the News

Before George Zimmerman goes on trial for the alleged murder of Trayvon Martin, his attorneys and Florida prosecutors are engaged in a legal battle concerning the qualifications of voice experts submitted by the prosecution.  The trial, expected to reawaken the dramatic controversy surrounding Martin’s death, is scheduled to begin in early June and will, in large part, turn on whether juror’s believe Zimmerman’s testimony that he was in legitimate fear of his life before the shooting.  As part of the trial, prosecutors will use audio experts to help jurors determine whether or not screams for help heard on the 9-1-1 call are coming from Martin or from Zimmerman – a tactic defense attorneys question by challenging the audio expert witnesses’ credentials.

Expert Witness Credibility

Attorneys cannot use any well-studied and intelligent witness to provide expert testimony to assist the trial.  The law sets standards to qualify not only the experts, but the field of study that supports their testimony.  Legal doctrine, established by the Supreme Court’s interpretation of Federal Rule of Evidence 702 in Daubert v Merrell Dow Pharmaceuticals, requires judges to act as gatekeepers, and only admit expert witness testimony in a subject matter that is based on scientific knowledge, relevant to the task at hand, and based on a reliable foundation.

Like most legal standards, the Daubert test does not provide any hard rules, but give judges a framework from which to make their decision.  At the heart of most arguments for or against an expert witness is whether or not the expert’s field of study has sufficient basis in acceptable science – often a difficult determination for judges to make.  As guidance, a judge relies on factors such as whether there is sufficient empirical testing to strengthen scientific assertions, whether the field has been subjected to peer review, the existence of standards controlling the field, and the degree to which the scientific theory at issue is generally accepted by other scientists.  While these factors provide guidelines, they leave room for significant debate about the qualifications of an expert witness to a trial.

It is left to lawyers to advance compelling arguments that push the envelope, and gradually expand, or contract, the definition of qualified expert witness in high profile cases like the Zimmerman murder trial.

Audio Experts In Trayvon Martin Murder Case

Florida prosecutors are attempting to use audio experts to help jurors identify the source of cries for help on the 9-1-1 call made shortly before Zimmerman killed Martin.  Zimmerman and his attorneys argue, as he claimed since the incident, that he felt threatened by Trayvon Martin and acted out of self defense in a violent struggle with the teenager.  The voice on the 9-1-1 tapes either belongs to Martin or to Zimmerman, and prosecutors hope to show that it was Martin’s voice crying for help – a fact that will chip away at Zimmerman’s claim of self defense.

Both of the prosecutors’ experts, one with prior experience testifying at trial and the other an audio engineer and forensic expert, are prepared to testify that the voice on the call is not Zimmerman, despite the defendant’s claims. Although Zimmerman’s attorneys maintain that the voice belongs to their client, who was crying for help from an alleged attack by Martin, the primary response to the audio experts is to claim that they do not meet the Daubert standards and, therefore, cannot be allowed to testify.  Defense attorneys argue audio expertise is not scientifically supported and that the tape could serve to confuse jurors, and hope that the judge’s broad discretion in qualifying experts will disallow the expert testimony.

Without knowledge of the field of audio identification and forensics, it is difficult to say for certain which way a judge will lean, but it appears prosecutors have the upper-hand.  Counting against Zimmerman’s defense team is the fact that one expert, Tom Owens, has national renown in the field and has previously qualified as an expert witness.  The other expert, Ed Primeau, is a forensic expert specializing in audio engineering – an impressive resume that seems relevant to the case at hand.  At first glance it seems that the expert witnesses will be permitted to testify and help jurors identify the voice on the 9-1-1 tape – the evidence is of significant importance and the audio experts in question have strong and previously recognized credentials.

Unquestionably, this pre-trial debate is merely a teaser for the drama to come in the Zimmerman murder trial; however, it presents a high profile example of the importance of expert witnesses and the legal standard to which they are held.

About Colin Holloway, Attorney at Law

LinkedIn Colin Holloway is an attorney operating in the Washington DC area. He is a graduate of Carnegie Mellon University and Emory University School of law, and has practice experience in criminal defense, personal injury litigation, mediation, and employment law.

About Colin Holloway, Attorney at Law

LinkedIn Colin Holloway is an attorney operating in the Washington DC area. He is a graduate of Carnegie Mellon University and Emory University School of law, and has practice experience in criminal defense, personal injury litigation, mediation, and employment law.