How many gunshots? When was the screaming? Pistorius's lawyer tears into first witness

Lawyers for Oscar Pistorius launched an aggressive defence on the first day of his murder trial, tearing into a witness who claimed to have heard a woman's screams as his girlfriend was killed. Advocate Barry Roux repeatedly and pointedly challenged Pistorius's neighbour and university lecturer Michell Burger, picking at potential inconsistences in her account.