George Zimmerman is not the one crying for help on the 911 tapes, experts say


The family of Trayvon Martin, the 17-year-old boy who was shot in Sanford, Fla on Feb. 26, is calling for an investigation into the case, questioning whether the man who fired his gun did so in self-defense.


George Zimmerman, the man who shot and killed 17-year-old teen Trayvon Martin in Florida last month, was not the one screaming for help on the 911 tapes of the incident, according to two forensic experts who analyzed the evidence. 

Trayvon Martin's family has insisted from the beginning that their son was the one heard screaming on the recordings, though Zimmerman's family disagreed, Slate reported. Zimmerman has claimed he shot Martin as an act of self-defense, and told police he was the one screaming for help.

In addition, a second ambulance called to the scene for George Zimmerman was canceled, according to fire department reports obtained by WKMG, a local CBS affiliate station in Florida. "You can cancel the second rescue," said a rescue worker heard on a recording of communications between ambulance teams and dispatchers.

A Martin family spokesman drew attention to the new records saying there was "not a chance" that the request would have been canceled if Zimmerman had been attacked and had his head bashed into the sidewalk by Trayvon Martin, as Zimmerman claimed.

More from GlobalPost: Trayvon Martin case: A timeline

Tom Owen, a forensic consultant and chair of the American Board of Recorded Evidence, used voice identification software to analyze the tapes at the Orlando Sentinel's request. Ed Primeau, a Michigan-based audio engineer and forensics expert, also examined the 911 recordings using different techniques. Both experts concluded that the voice calling for help is not Zimmerman, according to the Sentinel. 

Owen used a program called Easy Voice Biometrics to compare Zimmerman's voice to the 911 call's screams, and it returned a 48 percent match, the Sentinel reported. To get a conclusive match with that quality of audio, the percentage should be higher than 90, Owen told the Sentinel. 

"As a result of that, you can say with reasonable scientific certainty that it's not Zimmerman," Owen said. He was unable to confirm the voice as Trayvon's, however, because he didn't have a sample of the teen's voice to use as comparison.

Primeau, who enhances audio and then analyzes it manually, also offered his professional opinion on the call. 

"I believe that's Trayvon Martin in the background, without a doubt," Primeau told the Sentinel. "That's a young man screaming."

Primeau said Zimmerman's call to the police minutes before the shooting provides a good standard for comparison, "because it captures his voice both at rest and in an agitated state," according to the Orlando Sentinel. 

Martin's murder has been the focus of national attention since the incident on February 26th. Three separate investigations of the shooting are being conducted, and the police chief of Sanford, Florida has stepped down temporarily. 

More from GlobalPost: Trayvon Martin Case: Seminole County to investigate shooting

See our complete Trayvon Martin case coverage.

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