Trayvon Martin case: Can a few seconds of audio change everything?

What does audio from the night George Zimmerman shot Trayvon Martin reveal, and which side of the case does it benefit?

"I'm begging you."

Audio expert Alan Reich claims that's what 17-year-old Trayvon Martin can be heard pleading in the background of a 911 call made by a Sanford, Fla., resident on the night Martin was fatally shot.

Reich also says the audio reveals George Zimmerman, who faces a charge of second-degree murder for killing Martin, talking like an evangelist or a carnival barker and saying, "These shall be," according to the Orlando Sentinel.

Zimmerman, a neighborhood watchman, claims he acted in self-defense when he shot Martin on Feb. 26, 2012. His attorney, Mark O'Mara, has hired his own expert to testify that the screams and cries for help on the tape are actually Zimmerman's.

FBI analysts reportedly listened to the tape but were unable to determine who was screaming.

 

As the judge in the case, Debra Nelson, handed down a series of victories for the prosecution Tuesday — Martin's marijuana use, suspension from school and history of fighting are off-limits during opening statements at Zimmerman's trial, and jurors won't be allowed to visit the scene of Martin's death — Zimmerman's defense is trying to block Reich and other audio experts from testifying.

O'Mara filed a motion last week saying that Reich doesn't explain how he came to the conclusions in his four-page report for the prosecution, Bay News 9 reported.

The motion also claims that audio expert Tom Owen's methodology isn't generally accepted by his peers, and that highly technical testimony from two other expert witnesses would only confuse jurors. O'Mara argues that the quality of the recording is too low to be analyzed at all.

Prosecutors filed their own motion last week requesting that the court prohibit evidence related to a Computerized Voice Stress Analysis test, which State Attorney Bernie de la Rionda calls unreliable and inadmissible.

Nelson has yet to rule on whether she will allow Reich's testimony, according to the Sentinel.

Reich claims another piece of audio, from Zimmerman's initial call to police before the altercation with Martin, reveals Zimmerman telling an operator, "These [expletive], they always get away, but not on me."

Audio from that call launched its own controversy in April 2012 when NBC News and a Miami NBC affiliate edited it to make it sound as though Zimmerman was racially profiling Martin, who was African-American.

On the edited tape, Zimmerman apparently says of the unarmed teenager, "This guy looks like he's up to no good. He looks black." The uncut audio reveals that Zimmerman mentioned Martin's race only when the 911 operator asked, "OK, and this guy, is he black, white or Hispanic?"

Zimmerman's trial is scheduled to begin June 10. He faces a maximum sentence of life in prison if convicted of second-degree murder.