South African athlete Oscar Pistorius is due back in court after the judge adjourned his murder trial when he broke down in tears during testimony.
Mr Pistorius sobbed on Tuesday as he recounted finding the body of his girlfriend Reeva Steenkamp on the toilet floor of his home.
He said he had shot her through the door after mistaking her for a burglar in the late-night incident last year.
Prosecutors in Pretoria contend he intentionally killed her after a row.
The 27-year-old Olympic and Paralympic sprinter, who is a double amputee, faces life imprisonment if convicted of murder.
If acquitted, South African law stipulates that the court must consider the separate, lesser charge of culpable homicide, or manslaughter, for which he could receive between six and 15 years in prison.
Mr Pistorius also faces charges of illegally firing a gun in public and of illegally possessing ammunition, both of which he denies.
There are no juries at trials in South Africa, and his fate will ultimately be decided by the judge, assisted by two assessors.
On Tuesday, Mr Pistorius gave his version of the lead-up to the shooting and the actual event.
In the early hours of Valentine’s Day 2013, he said, he had got up from bed to bring in some fans he had left outside, in order to cool his bedroom.
When he heard a window opening in the bathroom, he said, he thought there was a burglar trying to get in.
Wanting to protect Ms Steenkamp, who was not sleeping, he had gone to get his gun in the dark.
“I whispered to Reeva to get down and phone the police,” he said.
He said he then went into the passage without his prosthetic legs and, overcome with fear, started screaming, and shouted for Ms Steenkamp to get to the floor.
“I heard a noise from inside the toilet, what I perceived to be someone coming out of the toilet,” he said tearfully.
“Before I knew it, I had fired four shots at the door,” he told the court.
After the shooting, Mr Pistorius said he had smashed in a door panel to get into the toilet, where he discovered what he had done.
“Whilst I leant over the partition to get in, I saw the key, so I took it and I unlocked the door, and I flung the door open, and I threw it open,” he said, sobbing.
“And I sat over Reeva and I cried… and um, I don’t know how long… I don’t know how long I was there for… She wasn’t breathing.”
As the athlete broke down, the judge adjourned the trial.
Mr Pistorius’s lawyer asked him to demonstrate his height without his prosthetic legs.
Gasps were heard in the overflow courtroom as he slowly walked on his stumps over to the mock-up of the toilet door, the BBC’s Pumza Fihlani reports.
His confident demeanour changed – on his stumps he seemed self-conscious, our reporter says.
The images were not visible to the outside world as his testimony is not being televised.
Earlier, the athlete described how the couple had spent a quiet evening together on 13 February, Ms Steenkamp doing some yoga as he spoke to his cousin on the phone.
He had then watched TV in bed with his head resting on her stomach and she would occasionally show him photos of cars she was looking at on her phone, he said. He said that they had bought Valentine’s Day gifts for each other.
Ms Steenkamp, a 29-year-old model, reality TV celebrity and law graduate, was hit by at least three bullets while in the toilet cubicle of Mr Pistorius’s home in Pretoria.
Mr Pistorius said in his statement at the start of the trial that he woke in the early hours and walked on his stumps to the balcony, pulled in two fans, closed the sliding door and drew curtains. He said that shortly before he had spoken to Reeva, who was in bed beside him.
He said he rejected prosecution claims that a witness heard arguing coming from the house before the shooting.
2. Bathroom noise
Mr Pistorius said he heard the bathroom window sliding open and believed that an intruder, or intruders, had entered the bathroom through a window which was not fitted with burglar bars.
“Unbeknown to me, Reeva must have gone to the toilet in the bathroom at the time I brought in the fans,” he said.
Mr Pistorius said he approached the bathroom armed with his firearm, to defend himself and his girlfriend, believing Ms Steenkamp was still in bed.
Both sides agree four bullets were fired. Ms Steenkamp was hit three times.
Mr Pistorius said he fired his weapon after hearing a noise in the toilet which he thought was the intruder coming out of the toilet to attack him and Ms Steenkamp.
He said he was in a fearful state, knowing he was on his stumps and unable to run away or properly defend himself.
Mr Pistorius said he rejected claims that he was on his prostheses when he shot at the door.
A witness told the trial she woke to hear a woman screaming and a man shouting for help. She said that after the screams she heard four shots.
Mr Pistorius said he went back to the bedroom after shooting at the toilet door, still shouting for Reeva. Lifting himself up onto the bed, he felt over to the right hand side of it and noticed Ms Steenkamp was not there.
Mr Pistorius said this was when he realised she could have been in the toilet.
5. Toilet door
Mr Pistorius said he went back to the bathroom but the toilet was locked, so he returned to the bedroom, pulled on his prosthetic legs, turned on the lights before bashing in the toilet door with a cricket bat.
Forensics expert Johannes Vermeulen told the court that the height of the marks on the door caused by the cricket bat suggest Mr Pistorius was on his stumps at the time.
6. Emergency calls
Mr Pistorius’s defence team say he then called security at the gated housing complex and a private paramedic service before carrying Ms Steenkamp downstairs.
A security guard claimed it was the other way round, and he had called Mr Pistorius first after reports of gunfire. However, phone records shown to the court revealed Mr Pistorius called the estate manager at 3:19am, a minute later he called the ambulance service and at 3:21am he called estate security.
A minute later he received an incoming call – estate security calling him back.
According to police phone expert Francois Moller, Mr Pistorius called his friend Justin Divaris a short time later and just after 4:00am he called his brother Carl.