>> i'd love to apologize. reporter: off camera within his voice quivering. pistorius taking the stand professing remorse to the family of his slain girlfriend, reeva steenkamp. >> i wake up everybody morning and you're the first people i pray for. >> reporter: her mother, expressionless. others in tears as he spoke. >> i can't imagine the pain and the sorrow and emptiness that i've caused you and your family. >> reporter: pistorius on trial for shooting and killing steenkamp through the bathroom door at his home in south africa last february, maintains he thought she was an intruder. >> i have terrible nightmares. about things that happened at night. i wake up and i smell -- i can smell -- the blood and i wake up to being terrified. >> reporter: the defense is also focusing on the double amputee's disability. >> i was born with a missing fibula. >> they claim that pretore yus