Oscar Pistorius swore in a South African courtroom Tuesday that he believed he was shooting an intruder last week - not girlfriend Reeva Steenkamp.
As the Olympian's lawyer read a sworn deposition claiming her death was an accident, prosecutors scoffed, saying he was hell-bent on murdering her.
He is charged with doing so in premeditated fashion.
Pistorius says he believed an intruder was in his house on Valentine's Day and he felt vulnerable because he was in bed without his prosthetic legs.
That's why he fired bullets through a bathroom door, killing Reeva Steenkamp, who prosecutors counter was hiding from him and cowering in there.
Officials say Pistorius' motive was simple: "I want to kill."
Prosecutor Gerrie Nel said the Olympian now only knew she was in there, he took the time to put his prosthetic legs on, walk 23 feet, and fire on her.
Oscar Pistorius claims he had no idea he was shooting at Steenkamp until he realized she was not in his bed. He said, "It filled me with horror and fear."
He claims he didn't have his prosthetic legs on when he fired, and only after that point did he put his legs on, walk over to the door and bash it open.
The 26-year-old sprinter says he bashed the door open with his cricket bat, discovered Steenkamp mortally wounded and carried her downstairs.
"She died in my arms," he said.
Prosecutors claim Pistorius and Steenkamp had just finished a shouting match when she fled and he fired four shots into the bathroom out of rage.
What do you think? Are you buying Oscar's defense?