Oscar Pistorius has been found not guilty of murdering Reeva Steenkamp.

The stunning development was revealed as Judge Thokozile Masipa read her summation of the evidence Thursday in front of a packed courthouse in Pretoria, South Africa, and a worldwide television audience.

Masipa has yet to hand down her final decision, which will come Friday. She did reveal in the waning moments of Thursday's summation that she determined Pistorious to have been "negligent," which means he could still be found guilty of culpable homicide, a conviction that comes with a maximum of 15 years in prison but carries no mandatory jail sentence. He also faces gun charges that carry potential prison sentences.

Oscar Pistorius reacts during judgement at the North Gauteng High Court in Pretoria. (REUTERS)

But a murder charge is out, for the time being anyway. The prosecution can appeal the decision and, if they do, Pistorius could still be convicted of murder, according to legal experts contacted by Yahoo Sports.

The prosecution, Masipa said in her summation, "failed to show requisite intention to kill the deceased, let alone premeditation."

All along, the prosecution pressed for a conviction for cold-blooded murder. But the Blade Runner has always maintained it was a tragic accident, that he shot his girlfriend in the pre-dawn hours of Valentine's morning last year in a moment of terror, believing that he was protecting them both from an intruder locked behind a bathroom door.

Masipa called Pistorius a "very poor witness," saying he was "evasive" in the face of prosecution questioning. Still, in her opinion that did not warrant a guilty verdict on the charge of premeditated murder, or even dolus eventualis – the grey area between premeditated murder and culpable homicide.

Under dolus eventualis, if Pistorius should have foreseen that his actions could result in death, yet recklessly proceeded anyway, it still would have been considered murder in South African law. That would have come with a minimum sentence of 15 years.

Masipa ruled out any murder conviction based on several key factors:

• Phone records support Pistorius' timeline of events.

Judge Masipa delivers her judgement in the trial of Oscar Pistorius. (REUTERS)

Pistorius relayed his version of events – that he thought an intruder had entered his home – minutes after the shooting took place, and that his version did not waiver later in questioning. Masipa agreed with the defense that it would be "highly improbable" for Pistorius to have made up this story so quickly, and that his version remained unwaivered throughout questioning even without access to his original statement or evidence from the scene.

Masipa determined that Pistorius did not subjectively foresee killing whoever was behind the locked bathroom door, and that it is clear to her that he genuinely believed Steenkamp to be in bed, not in the toilet.

"To find otherwise would be tantamount to saying that the accused's reaction after he realized that he shot the deceased was fake, that he was play acting merely to delude the onlookers at the time," Masipa said.

Pistorius could still be convicted of murder if the prosecution chooses to appeal.

The main point of contention is the interpretation of the law around dolus eventualis. In her summation, Masipa said murder with dolus eventualis is when someone foresees they could cause death, but recklessly proceeds anyway. It could be argued that it should be interpreted as when someone ought to foresee they could cause death, but recklessly proceeds anyway.

However, if Pistorius is convicted of culpable homicide and the judge hands down a stiff sentence, it's highly unlikely that the state will appeal. If she acquits him entirely, an appeal would be expected.