Audio experts differ on 911 call screams in Zimmerman case; Defense may ask for delay

SANFORD, Fla. — Audio experts gave differing opinions on whether screams for help captured on 911 calls were those of George Zimmerman or the 17-year-old teen he fatally shot last year in Sanford.

One audio expert said in a report released Tuesday that the screams came from Trayvon Martin, while another audio expert said the shouts were a mix of Martin and Zimmerman.

Attorneys prosecuting Zimmerman on second-degree murder charges hired the audio experts to compare samples of Martin's and Zimmerman's voices with the shouts from the 911 calls.

Martin's family claims the voice is that of the South Florida teen. Zimmerman's father has said in court he believes the cries are from his son.

Zimmerman's attorney, Mark O'Mara, told Channel 9 Tuesday he may ask for a delay in the trial later this month.

In one of the recently released reports, an audio expert in New Jersey states that one second into the now-infamous 911 call, Zimmerman is heard making what sounds like a religious proclamation, "These shall be," while Martin simultaneously says, "I'm begging you," in a tone described as loud, high-pitched and distressed.

"It may be the defense's biggest nightmare," said WFTV legal analyst Bill Sheaffer.

O'Mara questioned the science behind the expert's statements.

"Presumably, if he heard it then scientific method would suggest that somebody else can do the same thing," O'Mara said.

No other experts have.

Although O'Mara is trying to get more time to build his defense against the new evidence by postponing the court date a few months, he hopes at the very least the judge keeps the experts from claiming what they think they heard on the 911 call.

"It's a well-known phenomenon called listener or analyst bias. If I tell you something that's going to show up on a tape, you're going to hear it much more so than if I just play you the tape," O'Mara said.

The amount of discrepancy on the 911 call between all of the expert witnesses could work in Zimmerman's favor.

O'Mara said this may be the biggest chance for the defense team to create reasonable doubt in the jury's mind.

The second analysis of the 911 call is not nearly as definitive as the first. A team of audio experts said they heard cries from both Martin and Zimmerman in the background of the call, but said it's difficult to distinguish between the two.

"In the end, you may back the battle of the experts and the jury will be left to sort it out," said Sheaffer.

Even before the evidence goes to the jury, the defense will have a chance to keep it out of the trial, arguing the science behind the audio studies is unreliable and that the mixed results prove it.

But Sheaffer said the science isn't new and it's likely the judge will allow it.

"The judge is likely to find, 'I think I'm going to let this in, let the jury hear it, let the jury decide what weight or credibility to give these expert witnesses,'" said Sheaffer.

Zimmerman is pleading not guilty, claiming self-defense. His trial is set for June 10.

Turn to WFTV.com on June 10 to watch the trial live online.

WFTV