Independent forensic experts Tom Owen and Ed Primeau both tell the Orlando Sentinel that the voice heard on the call does not match Zimmerman's. Owen says he used voice match software to determine that there is only a 48% chance that the voice crying for help is Zimmerman's. A positive match would have resulted in a 90% reading.
"As a result of that, you can say with reasonable scientific certainty that it's not Zimmerman," Owen says.
Audio expert Ed Primeau adds: "I believe that's Trayvon Martin in the background, without a doubt... that's a young man screaming."
Zimmerman earlier told police he was the one screaming for help on the 911 call because 17-year-old Martin was attacking him.
The US Department of Justice could bring a hate crime charge against the 28-year-old self-appointed neighborhood watch captain based on evidence that the incident was motivated by racial bias. Though Owens and Primeau didn't touch on it, some say Zimmerman can also be heard whispering about "f**king coons" as he described Martin's location to the 911 operator.
Zimmerman claims he suffered a broken nose and wounds to the back of the head because of his fight with Trayvon. But new video from a Sanford police station shows him without any visible bruises or cuts shortly after the incident.
Martin's mother Sybrina Fulton recently joined Twitter to keep up with all the support on social media. "Thanks for all of the support... please continue to pray for our plight of Justice for Trayvon Martin," she recently tweeted.