Two audiotape recordings have made the news this week in connection with legal proceedings. Both involve high-profile cases, one on a national level and the other one locally.
The judge in the second-degree murder case of Florida neighborhood watchdog George Zimmerman (who is charged with slaying teenager Trayvon Martin) excluded expert testimony offered by the prosecution deciphering and interpreting an audio recording of a 911 emergency call. Although the judge allowed the jury to hear the recording, she disallowed the analysis on grounds that the techniques used were not "reliable" for purposes of allowing the experts to testify as to whose voice is being heard on the tape screaming for help or the precise wording.
Meanwhile, a surreptitiously made tape-recording of a conversation between Michael Brodkorb, the fired communications chief of the Republican caucus in the Minnesota Senate, was revealed by an anonymous source.
The ex-aide, who is in the midst of a contentious and highly costly lawsuit, secretly taped several conversations with a leader of the senate, Michelle Fischbach, shortly after he was abruptly fired following disclosure of an intimate affair between him and then-Senate Majority Leader Amy Koch. The recordings, made without Fischbach's awareness, reflect her misgivings about Brodkorb's firing, which could come in handy when Brodkorb's case goes to trial next summer.
The two tapes — the confrontation between Martin and Zimmerman, which led to a fatal finale, and the Brodkorb-Fischbach one, which followed the discharge decision — raise a number of points about the use of tape recordings in the legal system.
The legal tale of the tape of the Martin-Zimmerman clash, in which Zimmerman asserts he acted in self-defense, turns on the propriety of methodology used by the experts in trying to ascertain who was saying what on the recording. The experts selected by the prosecution came up with a few phrases that others could not hear and also opined that the voice beseeching for assistance was that of the slain youth, which bolsters the prosecution's murder charge.
Expert witness testimony plays a major role in litigation, but before it is admissible, it must be cleared by a judge. Under the general rules of evidence, in most jurisdictions, judges must determine that the testimony to be offered by an expert will "assist" the jury and is based upon "reliable principles and methods" and "generally accepted" by other knowledgeable individuals.
The "reliability" and lack of general acceptance factors doomed the proposed testimony by the prosecution's audio experts in the Florida fracas. Those criteria have been the bone of much controversy in connection with expert witness testimony, dating back at least two decades to a decision in the mid-1990s by the U.S. Supreme Court, written by Justice Harry Blackmun of Minnesota, in which the high court established standards for allowing expert witness testimony in federal court cases. Most of those standards are followed, in varying forms, by state courts as well.