South African runner Oscar Pistorius has taken the stand at his trial, as his lawyers try to convince the court he is not guilty of murdering his girlfriend.
Before beginning his testimony Monday, Pistorius, talking through tears, offered an apology to the family of Reeva Steenkamp.
"I'd like to apologize and say that there's not a moment and there hasn't been a moment since, since this tragedy happened, that I haven't thought about your family. I wake up every morning and you're the first people I think of, the first people I pray for. 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 that when she went to bed that night she felt loved. I've tried to put my words on paper many, many times to write to you, but no words would ever suffice."
Prosecutors, who wrapped up their case last month, say Pistorius shot Steenkamp intentionally at his Pretoria home last year.
The defense says Pistorius thought he was shooting at a nighttime intruder when he fired his gun through a bathroom door. The shots hit and killed the 29-year-old Steenkamp.
Pistorius has pleaded not guilty to charges of premeditated murder and three firearm-related offenses. If convicted, he faces 25 years to life in prison.
Pistorius is known as the "blade runner" for his carbon-fiber prosthetic legs. He became the first double-amputee to compete in the Olympics when he ran at the 2012 games in London.