Zimmerman defence: Real doubt means your decision is done

A jury has begun deliberations in the murder trial of a Florida neighbourhood watchman who shot dead an unarmed black 17-year-old last year.

Defence lawyer Mark O'Mara told the sequestered jury in his closing arguments earlier on Friday that Mr Zimmerman's guilt had not been proven beyond reasonable doubt. He said the shooting of Trayvon Martin was in self-defence.

"Do we think he just may have acted in self-defence?" he told the jury. "If you reach that conclusion, you get to stop."

The prosecution's case was built on a series of "could've beens" and "maybes", he added.

Mr Zimmerman could be acquitted, or convicted of second-degree murder or manslaughter.