The six-time Paralympic champion was found not guilty of premeditated murder or common law murder, but has been convicted of culpable homicide [manslaughter].
The double amputee denied murder by claiming that he mistook his girlfriend for an intruder when he fired four gunshots through a toilet door at his home in Pretoria, South Africa in the early hours of Valentine's Day last year.
Steenkamp's mother June told NBC News: "This verdict is not justice for Reeva. I just want the truth. He shot through the door and I can't believe that they believe it was an accident.
"I really don't care what happens to Oscar. It's not going to change anything because my daughter is never coming back. He's still living and breathing and she's gone, you know, forever."
Pistorius could face a maximum term of 15 years in prison, but could also be given a suspended sentence when he returns to the High Court in Pretoria for sentencing on October 13.