The South African athlete was found guilty last month of culpable homicide in the 2013 Valentine's Day death, but was cleared of murder.
Culpable homicide is a charge similar to manslaughter.
JOHANNESBURG — A South African judge on Friday convicted athlete Oscar Pistorius of "culpable homicide" in the death of his girlfriend, Reeva Steenkamp.
A conviction of culpable homicide, the term for manslaughter in South Africa, carries a maximum 15-year prison sentence. Pistorius had already been cleared of murdering Steenkamp.
Pistorius has been granted bail and will return to court on Oct.13 to find out whether he will be imprisoned and, if so, for how long.
A day earlier, Judge Thokozile Masipa said state prosecutors had failed to prove Pistorius, 27, was guilty of premeditated or second-degree murder.
However, Masipa found the actions by Pistorius — an Olympic and Paralympic athlete known as the Blade Runner for his use of specially designed prosthetic legs — to be "negligent."
Reading a lengthy explanation of the evidence and charges, Masipa told the court Thursday that she found Pistorius "acted too hastily and used excessive force" when he fired four times into the door of a toilet stall in his apartment, killing Steenkamp, 29, on Valentine's Day in 2013.
Masipa's decision to acquit Pistorius of murder was met with criticism from South Africans.
"Culpable homicide is not enough. The life lost doesn't get justice," said entrepreneur Nzolo Ezee Bidla, 25, on Friday, as he sat glued to the TV in a Johannesburg bar.
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.
Pistorius, who stood calmly with his hands folded in front of him as Masipa delivered her final verdict Friday, had denied the prosecution's claims that he had deliberately shot Steennkamp in the early hours of Feb. 14 last year.
Prosecutors accused Pistorius of intentionally killing her by firing through the door of the stall where, they alleged, she had taken refuge following an argument.
Pistorius claimed he thought Steenkamp was in bed and that he accidentally shot her through the bathroom door, mistakenly believing there was an intruder in his home.
As the track star prepared to spend a month waiting for sentencing, some South Africans said he has already suffered enough.
"I think they must forgive him," said bartender Thato Nailane, 25. "He is suffering emotionally. A light sentence would be better. He suffered for (6 months) being on trial."
Mannie Witz, a criminal defense attorney in Johannesburg, said state prosecutors could lodge an appeal but that the Pistorius defense team is unlikely to do so.
"There is still a long way to go," he said, adding he doubted Pistorius would get the full jail term.