Audio released as probe into killing of teenager announced

The US Department of Justice has announced an investigation into the shooting of an unarmed black teenager in Florida.

Trayvon Martin, 17, was shot dead by George Zimmerman, 28, while Martin was walking through a gated community in a suburb of Orlando last month.

Mr Zimmerman called police on 26 February, reporting there had been break-ins in the community, and that there was "a real suspicious guy" who "looks like he's up to no good".

Jonathan Blake reports.