Double-amputee Olympian sprinter Oscar Pistorius is set to return to the witness stand Tuesday to continue answering questions about why he shot his girlfriend, Reeva Steenkamp, in the early hours of Valentine's Day last year.
Pistorius, 27, has yet to be cross-examined about the Feb. 14, 2013, shooting — and that wrenching testimony could be the dramatic climax of a trial that has transfixed viewers around the world.
In his first day of testimony Monday, Pistorius showed anguish and remorse, testifying that he is ravaged by grief and haunted by memories of the fatal shooting of Steenkamp.
Here are the high points of the South African superstar's first day on the witness stand:
Pistorius began his testimony by apologizing to the parents of Steenkamp, 29, who died from wounds after the athlete shot her through a bathroom door in his home.
"There hasn't been a moment since this tragedy happened that I haven't thought about your family," Pistorius said while Steenkamp's mother, June, looked stoically at him in the courtroom.
"I can't imagine the pain and the sorrow and the emptiness that I've caused you and your family. I was simply trying to protect Reeva. I can promise you that when she went to bed that night she felt loved," he said.
He has said he mistook Steenkamp for an intruder. Prosecutors allege that he killed her after a heated argument.
Too Scared to Sleep
Pistorius told the court he is taking antidepressant medication and is tortured by panic attacks.
"I have terrible nightmares about things that happened that night where I wake up and I can smell the blood," Pistorius said. "If I hear a noise, I always wake up just in a complete state of terror, to the point where I would rather not sleep."
Pistorius described a fit of panic that drove him to hide in a closet one day.
"I climbed into a cupboard, and I phoned my sister to come and sit by me, which she did for a while," he said.
Memories of a Mother
Pistorius told the court about the positive influence of his mother, Sheila. He said he was stricken with grief after she died when the athlete was just a teenager.
"My mother had a lot of security concerns," Pistorius said, adding that his family was struck by home break-ins and carjackings throughout his childhood.
He said his mother kept a firearm "under her bed, under the pillow in a padded leather bag."
Fearful of Crime
Pistorius told the court that he felt vulnerable to crime — a potential attempt to explain his claim that he reacted to what he thought was a threatening intruder in his bathroom by firing his 9mm pistol.
"I think everybody in South Africa has been exposed to crime at some point," he said.
He said he had occasionally been trailed by unidentified people while driving home.
Pistorius also alluded to a 2012 incident in which he was allegedly assaulted at a social function and was forced to have stitches on the back of his head.
Judge Thokozile Masipa granted an early adjournment Monday because she said Pistorius looked "exhausted." He told the court he had not slept the night before.
"I'm just very tired at the moment. ... I think it's a lot of things going through my mind," he said. "The weight of this is extremely overbearing."
Pistorius is charged with premeditated murder and faces 25 years to life behind bars if convicted.
The Associated Press contributed to this report.