NEW : The FBI asks for more time to prepare to arrest agent Peet van Zyl . An acoustics expert is grilled about whose screams neighbors heard . Pistorius is accused of deliberately shooting his girlfriend , Anna Steenkamp . He says he shot Steenkamp accidentally in his bedroom , mistaking her for an intruder .
NEW : The prosecution asks for more time to prepare to question agent Peet van Zyl . An acoustics expert is grilled about whose screams neighbors heard . Pistorius is accused of deliberately shooting his girlfriend , Reeva Steenkamp . He says he shot Steenkamp accidentally in his bathroom , mistaking her for an intruder .