An emotional Oscar Pistorius has taken the stand as a witness in his defence in his trial for killing his girlfriend Reeva Steenkamp on Valentine's Day a year ago.
The Paralympic gold medallist is accused of premeditated murder, but claims he shot the model though a locked toilet door believing she was an intruder.
Pistorius apologised to Reeva Steenkamp's family, telling the court he had "terrible nightmares" since shooting dead his girlfriend and often woke up smelling blood, AFP reports.
Sobbing and with his jaw trembling as he took the witness stand in his defence, Pistorius said he did not intend to kill the 29-year-old.
"I want to take this opportunity to apologise to Mr and Mrs Steenkamp," he said, at times barely audible as he sobbed. Pistorius said he was "trying to protect Reeva" on Valentine's Day last year.
"I can promise that when she went to bed that night she felt loved."
"There isn't a moment, or hasn't been a moment since this tragedy happened that I haven't thought about your family."
"I can't imagine the pain and sorrow and the emptiness that I've caused you and your family."
In the tribunal, Ms Steenkamp's mother June, flanked by other relatives, stared at him stony-faced during the apology. She has sat through weeks of gruesome evidence, including brutal images of her dead daughter.
The athlete was speaking publicly for the first time about the events surrounding Steenkamp's death.
Since that fateful night, "I've had terrible nightmares," he said, adding: "I wake up at night smelling blood." He also said he has been on anti-depressants since the shooting.
Pistorius told the court that on one occasion after waking in the middle of the night he crawled into a cupboard because he was so scared.
Monday's session seemed just as harrowing for the sprinter.
The court was forced to adjourn for the day ahead of schedule after defence lawyer Barry Roux said his witness was exhausted by a lack of sleep and the day's ordeal.
"Well he does look exhausted, he sounds exhausted," said Judge Thokozile Masipa, granting the defence an adjournment until Tuesday.
After five weeks of prosecution testimony, Monday was the first day of Pistorius's defence.