PRETORIA, South Africa (AP) — Oscar Pistorius began testifying at his murder trial Monday by apologizing to the family of the girlfriend he shot dead last year, saying as he held back sobs that he was trying to protect Reeva Steenkamp when he fired four times through a toilet cubicle door.

The double-amputee athlete also said he has had nightmares regularly since the shooting, which he claims was accidental, and has been taking antidepressant medication for over a year.