New video of George Zimmerman at police department 3 days after shooting

SANFORD -- Newly released video of George Zimmerman taken just days after he shot and killed 17-year-old Trayvon Martin is raising some questions.

The surveillance video, obtained from Sanford police by CNN, shows Zimmerman at the Sanford Police Department on Feb. 29, three days after the shooting.

A close look at the video of Zimmerman, who is seen walking up a stairway, shows a bandage on the back of his head.

Zimmerman has claimed Trayvon Martin attacked him the night he shot the teen. New evidence released last week showed clearer pictures of cuts on Zimmerman's head.

Sanford police would not immediately comment on why Zimmerman was at the station three days later, saying they cannot talk about the investigation.

George Zimmerman is charged with second-degree murder for shooting Trayvon Martin. He has pleaded not guilty.

The new video comes as both prosecutors and Zimmerman's defense lawyers file new motions in the case.

Defense attorney Mark O'Mara said he wants more time to review the evidence, asking for 30 more days to review some of it before it's released to the public.Meanwhile, prosecutors have asked a judge to seal evidence such as crime scene photos and Trayvon Martin's cell phone records until the trial.Judge Kenneth Lester has scheduled a hearing on the motions for June 1, a week from Friday.