Another Follow-up of the Day: Enhanced Video of Zimmerman in Trayvon Martin Shooting

In a reversal from last week's coverage, ABC News says the police surveillance footage of George Zimmerman in the Trayvon Martin shooting "shows the neighborhood watch captain with an injury to the back of his head," now that it has been digitally improved by Forensic Protection Inc. The "gash or mark" on Zimmerman's head would lend support to his claim that he acted in self-defense when he shot Martin.

Meanwhile, over the weekend, The Orlando Sentinel reported that two audio experts believe the voice heard calling for help in the background of the 911 call to police is not that of Zimmerman. One of the experts, Tom Owen -- who is chair emeritus at the American Board of Record Evidence — believes the tests indicating it isn't Zimmerman's voice would stand up in court.

"You can say with reasonable scientific certainty that it's not Zimmerman," Owen said. If he is proved right, then the 911 call would raise questions about Zimmerman's claim of self-defense.

[abcnews / orlandosentinel]