South African athlete Oscar Pistorius is standing trial accused of murdering his girlfriend Reeva Steenkamp, a 29-year-old model and law graduate, at his home in Pretoria on 14 February 2013.
The double-amputee sprinter, 27, has pleaded not guilty to all charges, including the "wilful and intentional murder of Reeva Steenkamp".
Here are details of the key evidence put before the court so far.
Oscar Pistorius' testimony
Mr Pistorius has told the court that on the night of the shooting the couple had dinner at about 19:00 local time (17:00 GMT) before watching television and falling asleep between 21:00 and 22:00.
He said he woke in the early hours and Ms Steenkamp asked him: "Can't you sleep, my baba?"
He told the court he could not sleep and that he had brought in two fans from the balcony. Mr Pistorius then described how he heard a noise from the bathroom.
"That's the moment that everything changed," he said. "I thought that there was a burglar that was gaining entry to my home."
Inside Oscar Pistorius's home
Mr Pistorius said he and Ms Steenkamp had dinner at about 19:00 before going to bed at 21:00. He said he woke in the early hours, spoke briefly to his girlfriend and got up to close the sliding door and curtains.
Judge Thokozile Masipa questioned the reliability of several witnesses who said they heard screams and gunshots between about 03:12 and 03:17, saying most had 'got facts wrong'.
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.
Mr Pistorius said he grabbed his firearm and told Ms Steenkamp, who he thought was still in bed, to call the police.
The judge said it made no sense that Ms Steenkamp did not hear him scream 'Get out' or call the police, as she had her mobile phone with her.
Mr Pistorius could see the bathroom window was open and toilet door closed. He said he did not know whether the intruders were outside on a ladder or in the toilet.
He had his firearm in front of him, he heard a movement inside the toilet and thought whoever was inside was coming out to attack him.
'Before I knew it, I had fired four shots at the door,' he said.
The judge said she did not accept that Mr Pistorius fired the gun by accident or before he knew what was happening. She said he had armed himself with a lethal weapon and clearly wanted to use it. The other question, she said, was why he fired not one, but four shots before he ran back to the room to try to find Ms Steenkamp.
Mr Pistorius said he went back to the bedroom and noticed that Ms Steenkamp was not there.
Mr Pistorius said this was when he realised she could have been in the toilet and rushed back to the bathroom.
Mr Pistorius said he screamed for help and went back to the bathroom where he found the toilet was locked. He returned to the bedroom, pulled on his prosthetic legs and turned on the lights before bashing in the toilet door with a cricket bat.
When the door panel broke, he found the key and unlocked the door and found Ms Steenkamp slumped on the floor with her head on the toilet bowl. He then carried her downstairs, where he was met by neighbours.
3D animation of the apartment
Mr Pistorius said he grabbed his 9mm pistol from under his bed and moved towards the bathroom on his stumps, telling Ms Steenkamp quietly to call the police.
"I got to the entrance of the bathroom, at the end of the passage. At this point I was certain that an intruder or intruders were there in my bathroom."
He said he saw the bathroom window was open and he screamed for Ms Steenkamp to call the police.
"I wasn't sure if somebody was going to come out of the toilet and attack me," he told the court. "I wasn't sure if someone was going to come up the ladder and point a firearm and start shooting. So I just stayed where I was and I kept on screaming.
"Then I heard a noise from inside the toilet - what I perceived to be somebody coming out of the toilet. Before I knew it, I fired four shots at the door."
Mr Pistorius said the gunshots left his ears ringing, and he kept on shouting for Ms Steenkamp to phone the police. He said he retreated back to the bedroom and found Ms Steenkamp was not in bed.
"At that point, the first thing I thought was maybe she got down onto the floor like I told her to, maybe she was just scared... I can't remember what I said but I was trying to talk out to her.
"It was upon that time, my Lady, that it first dawned upon me that it could be Reeva that was in the bathroom or in the toilet. I jumped out of the other side of the bed and I ran my hands along the curtains to see that she wasn't hiding.
"I didn't want to believe it was Reeva in the toilet, I was so scared that someone was coming in to attack us. I made my way inside the bathroom... I tried to grab the handle, rip open the door. I pushed the door to open and it was locked.
"I ran back to the room, I opened the curtains, opened the doors and shouted from the balcony for help. I screamed, 'Help, help, help.' I screamed for somebody to help me.
"I put my prosthetic legs on. I ran as far as I could back to the bathroom, I ran into the door. It didn't move at all. I tried to kick the door but nothing happened."
Mr Pistorius told the court how he went back to the bedroom, picked up a cricket bat and started hitting the toilet door in a bid to open it.
He said he hit the door about three times and then managed to pull a plank out of it. Eventually he found the key on the floor and unlocked the door.
"I sat over Reeva and I cried, I don't know how long... I don't know how long I was there for," he told the court.
The prosecutor's view
The prosecution says Mr Pistorius deliberately shot dead Ms Steenkamp after the couple had had an argument on Valentine's Day.
Chief prosecutor Gerrie Nel said Mr Pistorius's account of the night was a fabrication and the pair had been arguing just before the shooting.
"You fired four shots through the door whilst knowing that she was standing behind the door," Mr Nel said.
"She was locked into the bathroom and you armed yourself with the sole purpose of shooting and killing her."
"That is not true," replied Mr Pistorius.
During cross-examination the prosecution has focused on the athlete's character and enthusiasm for firearms.
The court was shown a Sky News report showing Mr Pistorius at a shooting range.
Mr Nel also showed the court a photograph of the effects of the shooting on Reeva Steenkamp's head.
Mr Pistorius refused to look at the photo saying: "I will not look at a picture where I am tormented by what I saw."
However, Mr Nel has repeatedly accused Mr Pistorius of using his emotions "as an escape" after he broke down a number of times in court.
"You're getting emotional now because you're getting frustrated because your version [of events] is improbable," Mr Nel said.
The prosecution has also highlighting a number of apparent inconsistencies between Mr Pistorius' bail application and his evidence in court.
The defence and prosecution also disagree about bangs heard that night and whether they were made by Mr Pistorius hitting the door with a cricket bat, or whether they were gunshots, or both.
A forensic analyst contradicted Mr Pistorius' claim that he was wearing his artificial legs when he tried to break open the toilet door with a cricket bat after realising Ms Steenkamp was inside.
Police Colonel Johannes Vermeulen said the angle and location of the marks on the door suggested Mr Pistorius was on his stumps. In court, Mr Vermeulen knelt down to swing the bat at the door to demonstrate.
"The marks on the door are actually consistent with him not having his legs on and I suspect they must be similar to the height that he was when he fired the shots," he told the court.
Ballistics expert Captain Christiaan Mangena told the court he believed Ms Steenkamp was standing up in the toilet cubicle, facing the closed door when she was hit in the right hip. The hole made by the bullet is labelled as A in the diagram below.
Ms Steenkamp then fell back onto a magazine rack next to the toilet before three more bullets were fired at the door, he said. One bullet missed her and ricocheted off the wall twice. Capt Mangena said fragments from this bullet (from bullet hole B) caused bruising on Ms Steenkamp's back - although the defence rejects this.
The expert said Ms Steenkamp was then hit by two more shots (causing bullet holes C and D), one in the arm and the other went through her left hand into her skull as she crossed her arms over her head to protect herself.
Capt Mangena said that after being hit in the head, she fell down and her head ended up on the toilet seat. He said the gun had been fired from at least 60cm (23 inches) from the door and no further than 3m. He added that Mr Pistorius was most likely not wearing his prosthetic legs at the time.
Correspondents say this is in line with Mr Pistorius' testimony that he pulled the trigger while standing at the entrance to the bathroom.
However, Capt Mangena said he believed there was a gap between the first and second bullet being fired, which contradicts the athlete's version of events. It corroborates evidence given by a neighbour who said she heard a shot, then a pause, then three further shots. It also suggests that Ms Steenkamp may have had time to scream before she fell to the floor, supporting the neighbour's testimony that she had heard a woman screaming.
However, pathologist Jan Botha, the first witness for the defence, said that if Mr Pistorius had fired his weapon in two quick bursts, as the defence suggests, Ms Steenkamp probably would not have had time to scream.
"If the shots were fired in rapid sequence, and these four shots could have easily been fired in four seconds, I think it's highly unlikely that she would have called out,'' said Mr Botha.
But, he said, he was "not a ballistician".
Some of Mr Botha's evidence also contradicted testimony given by state pathologist Gert Saayman who said vegetable matter in Ms Steenkamp's stomach suggested she had eaten around two hours before her death. Mr Pistorius' team says she had been asleep for longer than that.
Mr Botha said analysing gastric contents was "a highly controversial and inexact science".
Prosecution witnesses - including one who lives on the nearby Silver Stream Estate - have testified to hearing a woman scream followed by gun shots, but the defence disputes their testimony, saying the only scream came from Mr Pistorius - after he had fired.
As there are no juries at trials in South Africa, Mr Pistorius's fate will ultimately be decided by the judge, assisted by two assessors.