Radiologist Johan Stipp was being questioned by defense lawyer Barry Roux on Friday, a day after Stipp described how Pistorius knelt at Reeva Steenkamp's side and struggled in vain to help her breathe by holding two fingers in her clenched mouth.
Pistorius shot Steenkamp in the bathroom of his home before dawn on Feb. 14 last year. He says he fired after mistaking Steenkamp for an intruder; prosecutors allege the Olympian intentionally killed Steenkamp after a loud argument.
