ABC News has re-digitized video of George Zimmerman taken shortly after Trayvon Martin's shooting.

The video was unveiled as an exclusive this morning on "Good Morning America." ABC was the first news organization to show the original tape.

Reporter Matt Gutman said the clearer video shows "what appear to be a pair of gashes or welts on George Zimmerman's head."

Neighborhood Watch volunteer Zimmerman has said he shot 17-year-old Trayvon in self-defense. The video shows Zimmerman arriving at the Sanford Police Department within an hour after the shooting.

Gutman said the video had been "clarified" by Forensic Protection Inc. Former FBI Special Agent Brad Garrett told ABC that the clearer video shows "marks on the back of Mr. Zimmerman's head."