Oscar Pistorius took the witness stand on Monday in South Africa and apologized to the family of Reeva Steenkamp for shooting her to death last year.
Weeping and speaking in a quavering voice, he described a life of insomnia and panic since the night of February 14, 2013, when he killed his girlfriend.
The double-amputee track star, 27, says it was a tragic error.
Investigators say otherwise, and he faces at least a 25-year sentence if convicted of premeditated murder in the shooting of the law graduate and model.
“I want to start by apologizing to Reeva’s family,” Oscar Pistorius said, barely able to answer his lawyer’s questions. “I was simply trying to protect Reeva.”
He has denied the murder charge, saying he believed he was shooting an intruder inside his home when he fired four rounds through a locked bathroom door.
Reeva Steenkamp, 29, was locked inside.
“I wake up in a complete state of terror,” he said in his first testimony since the bombshell trial began. “I wake up in a panic. I can smell the blood.”
South Africa doesn't have jury trials, so it's up to a judge to determine the fate of Pistorius, who prosecutors say is both possessive and trigger-happy.
Prosecution witnesses have testified that they heard female screams before shots coming from his house in the early hours of Valentine’s Day in 2013.
Throughout the trial so far, Pistorius has displayed a range of emotions in court as prosecutors seek to prove that he killed Steenkamp in a violent rage.
He has sobbed, prayed, thrown up, buried his face in his hands and covered his ears at some of the testimony, making for an even bigger media spectacle.