Cleared of murder and premeditated murder, Oscar Pistorius was convicted on Friday of culpable homicide of his girlfriend Reeva Steenkamp on Valentine's Day last year.
Judge Thokozile Masipa ordered Pistorius to stand before she delivered the verdict, AP reported.
The sentence for a culpable homicide conviction is at the judge's discretion, and it can range from a suspended sentence and a fine to up to 15 years in prison. Sentencing was to be announced at a later date.
Pistorius was also convicted on one of three unrelated firearm charges. The judge ruled that the athlete was guilty of unlawfully firing a gun in a public place when a friend's pistol he was handling discharged under a table in a restaurant in Johannesburg in early 2013 — weeks before Steenkamp's killing.
Pistorius was acquitted on two other gun charges, including a count of firing a gun in public and a count of illegal possession of ammunition in the Pretoria home where he killed Steenkamp.
The Pretoria courtroom was packed for the ruling in the case against 27-year-old Pistorius, once a globally admired celebrity who competed against able-bodied athletes at the 2012 Olympics in London. His brother, Carl, was there in a wheelchair because of injuries suffered in a recent car crash. So were Steenkamp's parents, June and Barry.
Steenkamp, a 29-year-old model, had been seeing the star athlete for only a few months before he killed her by shooting four times through a closed toilet door in his home in the pre-dawn hours of Valentine's Day last year. Pistorius said he thought an intruder was in the toilet and about to attack him; the prosecution said he intentionally killed her after an argument.
Judge Thokozile Masipa, wearing a red robe, unveiled her analysis of the case after saying little throughout the sensational six-month trial as lawyers argued and witnesses testified about the shocking killing. South Africa does not have a jury system, and judges customarily issue verdicts only after explaining their reasoning.
The moments that shaped the trial
'I was woken by blood-curdling screams'
The former neighbor of Pistorius, Michelle Burger, was the first witness to testify at the trial.
She said she was woken by terrible screams of a female, followed by a male and then the sound of four gunshots.
"It was very traumatic from me. You could hear it was blood-curdling screams. It leaves you cold, you can't translate it in words, the anxiousness and fear in her voice."
The defence team attacked the witness verbally, accusing her of being inconsistent by changing her story from her initial statement.
Pistorius says sorry, testifies
Pistorius took the stand for seven days in April and apologized to her family.
"I would like to take this opportunity to apologize to Mrs and Mr Steenkamp. I would like to apologize and say there's not a moment and there hasn't been a moment since this tragedy happened that I haven't thought about your family," he said as he faced Reeva's mum, June.
"I wake up every morning and you're the first people I think of, the first people I pray for. I can't imagine the pain and the sorrow and the emptiness that I've caused you and your family. I was simply trying to protect Reeva. I can promise that when she went to bed that night she felt loved."