Reporting that it has had the video "clarified" by a forensics company, ABC News is now saying that a police surveillance recording of George Zimmerman "shows the neighborhood watch captain with an injury to the back of his head."

Last Wednesday, when it broke the news of the video's existence and broadcast it, ABC News said "no abrasions or blood can be seen in the video." We posted about that report, while noting that "it is possible that paramedics cleaned any blood before Zimmerman arrived at the police station."

Now, ABC News says, Forensic Protection Inc. has digitally improved the clarity of the video and there appears to be a "gash or mark" near the top of the back of Zimmerman's head.

The network adds that "the enhanced video does not show any visible injury to Zimmerman's nose, nor any signs of blood on his shirt."

Zimmerman, 28, says he shot and killed 17-year-old Trayvon Martin on Feb. 26 in Sanford, Fla., in an act of self defense. The incident has become a national story as Martin's family and supporters have questioned why Zimmerman was never arrested and whether the African-American teen was the victim of racial profiling before and after his death.

Zimmerman's family has said that medical records will support his claim of being injured. If the video does show an injury, that too could support his claim.

ABC News adds that:

"The initial police report noted that Zimmerman was bleeding from the back of the head and nose, and his lawyer later claimed that Zimmeran suffered a broken nose. After receiving medical attention at the scene of the shooting, it was decided that he was in good enough condition to travel in a police cruiser to the Sanford, Fla., police station for questioning. He did not check into the emergency room following the police questioning."

Earlier, we reported about experts telling The Orlando Sentinel that they do not think it was Zimmerman's voice calling for help in the background of a 911 call that night.

Update at 3:05 p.m. ET. More On The Company That Did The Analysis:

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