A security guard says Oscar Pistorius told him on the phone that everything was "fine,'' after neighbors reported gunshots coming from the home of the South African track star on the night he shot and killed his girlfriend.

The guard testified Friday that Pistorius called him back moments later and started crying before the line went dead. The court also heard from a former girlfriend who said Pistorius always carried a firearm when they dated and that he once fired his gun out of the sunroof of a car.

Prosecutors say Pistorius shot and killed Reeva Steenkamp after an argument. Pistorius says he fired through a bathroom door thinking she was an intruder.

Another witness in the murder trial of South African Olympian Oscar Pistorius says the double-amputee runner knelt at the side of his girlfriend and prayed after he shot her in his home on Valentine's Day 2013.

Radiologist Johan Stipp testified Thursday that Pistorius struggled in vain to help model Reeva Steenkamp breathe, and says Pistorius told him,

"I shot her.  I thought she was a burglar.  I shot her."

Pistorius has said he fired through a bathroom door at someone he thought had broken into his home.

Prosecutors argue Pistorius shot Steenkamp after an argument.