CCTV of man accused of killing Trayvon Martin
New video footage has emerged of the man accused of killing an unarmed teenager in Florida.
Some say the police surveillance pictures of George Zimmerman raise questions about his claim that Trayvon Martin attacked him.
Mr Zimmerman claims he shot the 17 year old in self defence, which is legal in Florida and many other US states.
The BBC's Jonathan Blake reports from Washington.
29 Mar 2012