Oscar Pistorius – a convicted killer, but not a murderer.

That was a South African judge's final assessment on Friday morning as she acquitted the Olympic and Paralympic hero of deliberately murdering his girlfriend Reeva Steenkamp, finding instead he negligently fired four shots into his bathroom in the most extraordinary case of mistaken identity on Valentine's Day 18 months ago.

The guilty verdict for culpable homicide, akin to manslaughter in Australia, carries a maximum penalty of 15 years prison, but in reality he is likely to receive far less.

Judge Thokozile Masipa also continued Pistorius' bail, rejecting the prosecution's claim that he might be a flight risk now he had been convicted of such a serious offence.

She set aside three days for sentencing, beginning on October 13.

Some legal experts were quick to speculate that Pistorius could even be given a suspended sentence, if Judge Masipa was to treat him as a first-time offender, and rule he had suffered enough in the wake of the tragedy.

Pistorius has shown so much emotion throughout the six-month trial, it came as some surprise that the runner remained stony-faced as the judge asked him to stand, and pronounced her verdicts.

She acquitted Pistorius of the premeditated murder, finding the prosecution had not provided a "strong circumstantial case" to prove the most serious charge on the books beyond a reasonable doubt.

The family and friends of Ms Steenkamp appeared distressed at the verdicts, one member of the tight-knit group reportedly saying they were all "very disappointed" with the verdicts, but  "were trying to stay strong".

The Myers family, who Reeva called her "Jo-burg family", appeared particularly distraught. Gina Myers, one of the young model and law graduate's best friends, sobbed throughout the final day of the judgment.

They were fortunately spared many details of Ms Steenkamp's death as Judge Masipa summed up the evidence. The court had previously heard graphic evidence of how and where the "Black Talon" ammunition struck Pistorius' girlfriend, including a fatal shot to her head.

In making her final judgment, Judge Masipa rejected huge swathes of the state's case, saying there was not enough evidence to provide a motive of intent to kill Ms Steenkamp.

In a judgment lasting about five hours, Judge Masipa also noted that Pistorius' conduct in the immediate aftermath of the shooting helped her form the view that he should be acquitted of second degree murder.

"He acted promptly in seeking help soon after the incident, he shouted for help, he called a friend, he called 911, he called security although he could not speak as he was crying ... he was seen trying to resuscitate the deceased," she said. "From the above it cannot be said that the accused did not entertain a genuine belief that it was not an intruder in the toilet."

However, as she had noted in her remarks on Thursday, she believed Pistorius had acted negligently. His actions in firing the shots were unreasonable and he used excessive force on the night in question, proving the charge of culpable homicide.

She noted the Olympian could and should have phoned the police or his Silver Woods estate private security guards before he opened fire. Indeed, she noted it would have taken less time to do that than grab his gun, walk towards the perceived danger and fire.

"The accused acted too hastily and used excessive force ...  in the circumstances, it was clear that his conduct was negligent," she said on Thursday.

On Friday morning, she also acquitted Pistorius of two unrelated firearms charges, but convicted him of recklessly handling a firearm in a crowded Johannesburg restaurant, causing it to discharge.

On that count, Judge Masipa said the accused asked a friend to pass him a loaded firearm in a crowded restaurant – an action in itself that was reckless.

"He may not have intentionally pulled the trigger, but that does not absolve him of the crime of negligently handling a firearm in circumstances where [people could be injured]," she said.

After the verdicts were formally stated, the question turned to whether bail should be revoked.

Pistorius has been at liberty on conditional bail since shortly after he was charged, and his defence counsel Barry Roux argued it should remain that way.

Prosecutor Gerrie Nel disagreed, saying the unlawful killing of another human being was a serious charge, and warranted the athlete being taken into custody pending what he described as a "probable" jail sentence.

Pistorius was taken into custody and to the cells below the court shortly before midday on Friday, pending Judge Masipa's decision.

Outside the court, a spokesman for the National Prosecuting Authority said while they respected the decision of Judge Masipa, the state was disappointed Pistorius wasn't convicted of premeditated murder.

A decision on whether to launch an appeal against the decision would not be made until after sentencing, which would take place on a date to be fixed.