Hugh Pickens writes "As the Trayvon Martin controversy splinters into a debate about self-defense, a central question remains: Who was heard crying for help on a 911 call in the moments before the teen was shot? Now the Orlando Sentinel reports that Tom Owen, a leading expert in the field of forensic voice identification sought to answer that question by analyzing the recordings. His result: It was not George Zimmerman who called for help. Owen, forensic consultant for Owen Forensic Services LLC and chair emeritus for the American Board of Recorded Evidence, used voice identification software to rule out Zimmerman. Another expert contacted by the Sentinel, utilizing different techniques, came to the same conclusion. Owen used software called Easy Voice Biometrics to compare Zimmerman's voice to the 911 call screams. 'I took all of the screams and put those together, and cut out everything else,' says Owen. The software compared that audio to Zimmerman's voice and returned a 48 percent match. Owen says to reach a positive match with audio of this quality, he'd expect higher than 90 percent. Owen cannot confirm the voice as Trayvon's, because he didn't have a sample of the teen's voice to compare however 'you can say with reasonable scientific certainty that it's not Zimmerman.'"