The 17-year-old's death has sparked a national conversation about racial profiling. Trayvon was fatally shot Feb. 26 after Zimmerman, a neighborhood watch volunteer, followed him because he said the teen looked suspicious.
Trayvon, who is black and wore a hooded sweatshirt, was unarmed; Zimmerman is described by police as white; his family says he is Hispanic.
No charges have been filed against Zimmerman. He had told police that Trayvon jumped him and smashed his head into the pavement. According to an initial police report, an officer noticed Zimmerman was bleeding from the nose and back of his head and showed signs of having been in a struggle.
David Notowitz, a forensic video expert, said the video of Zimmerman entering the police station appeared to one of high quality and resolution and could be analyzed to determine if Zimmerman's nose is broken or there were wounds on his back.
Notowitz, founder of the National Center for Audio and Video Forensics, said the video supplies shots of Zimmerman at various angles which could be enhanced, studied and compared.
A video expert could use the footage to zoom in on Zimmerman's head, neck, nose and jacket, he said. Experts, such as doctors, could then analyze the pictures.
Zimmerman's lawyer and friends have spoken in defense of the neighborhood watch volunteer, saying he is not a racist. He has dropped from sight since the killing and has not made any public remarks.
Despite the police decision not to charge Zimmerman at the time, several other probes are ongoing. The U.S. Justice Department has opened an investigation, and a Seminole County Fla., grand jury is considering possible charges. The grand jury is likely to convene April 10.