A voice expert says he doesn't assume it's one person crying for help in the background of a 911 call at the center of George Zimmerman's second-degree murder trial. The defense expert's testimony Monday night refutes state experts who imply it's Trayvon Martin crying for help seconds before Zimmerman shot him to death. The prosecution wants jurors to hear that expert testimony, but defense attorneys want it kept out of the trial.
The testimony is about a 911 call from a witness.
Defense expert James Wayman says he can't even conclude it's a single person crying for help in the call.
Previous expert testimony based on spectrogram analysis -- or visual representations of sound -- ruled out Zimmerman as the one crying for help. But Wayman says many variables can influence a speaker's spectrogram.
"I'm testifying over Skype. I'm using perhaps a different voice. I'm emphasizing words in a slightly different way than if you and I were, say, sitting around in your living room drinking coffee. We'd be talking in a different way, and the spectrogram would be different."
Wayman has researched speaker recognition for the Department of Defense and other government agencies. He says spectrograms are not an accepted technology in speaker recognition.
The testimony came during a late-evening hearing that at one point left the courtroom in darkness. The hearing will continue Wednesday with evidence from an expert for the state.
Zimmerman says he shot and killed Martin in self-defense. Jury selection continues Tuesday.
To see more, visit http://www.wmfe.org.
