George Zimmerman describes Martin shooting

The defence for George Zimmerman, who shot unarmed black teenager Trayvon Martin in February, has released a video showing the Florida neighbourhood watchman describing his version of events to the police.

In the video, he maintains he opened fire after the 17-year-old had repeatedly hit his head on the ground and reached for Mr Zimmerman's gun.

The defence first posted the video on a website set up publicise their case and raise funds for Mr Zimmerman's legal costs.