Pistorius details questioned by prosecution

Pretoria, South Africa ( - South African sprinter Oscar Pistorius remained on the witness stand Thursday in his murder trial and had his account of the events on the night of the killing of girlfriend Reeva Steenkamp questioned in a cross-examination by the prosecution.

Pistorius, the double-amputee runner, shot and killed Steenkamp on Feb. 14, 2013 in the bathroom of his home. He gave his account of what happened that night on Tuesday, saying he believed Steenkamp was an intruder and mistakenly killed her.

Prosecutors have maintained that Pistorius knew Steenkamp was in the bathroom when he fired four shots through the door.

Lead prosecutor Gerrie Nel asked Pistorius how he fired the shots and the defendant said he didn't remember how many shots he fired.

"I remember it being four shots in quick succession," Pistorius said. "I remember firing shots, I was later told it was four shots.

Countered Nel, "You don't remember how many but you remember quick succession?"

Pistorius answered yes.

Nel said Pistorius previously stated that "before I knew it, I had fired four shots at the door. My ears were ringing."

Later, Nel asked Pistorius why he fired at the bathroom door.

"I heard a noise which I perceived to be the intruder," Pistorius answered, adding again that the shooting was an accident.

Pistorius later suggested that police moved some items before taking a picture of the crime scene and Nel said the defendant's account was not plausible.

"Your version is so improbable that nobody would ever think it's reasonably possible," Nel said toward the end of Thursday's proceedings.

Pistorius is expected to return to the stand on Friday.

The trial, which began on March 3, is being broadcast throughout South Africa and other parts of the world.

Pistorius is not being shown as he testifies. Only the audio portion of his statements are audible as the cameras take shots of the judge, attorneys and court room.

Judge Thokozile Masipa will decide guilt or innocence in the case, as South Africa does not have trial by jury.

In addition to the murder charge, Pistorius also faces charges of contravening South Africa's Firearms Control Act.

The murder charge could carry a sentence of life in prison. There is no death penalty in South Africa.

Steenkamp, who was 29 years old, was a model and reality television star in South Africa.

Pistorius, known as the "Blade Runner," made history at the London Olympics in 2012 when he became the first double-amputee runner to compete in the Games. He had both legs amputated before he was a year old after being born without fibula bones and runs on prosthetic blades.

The International Association of Athletics Federations (IAAF) had initially said that his prosthetics were considered technical aids and in violation of an IAAF rule. But the Court of Arbitration for Sport later overturned that decision, making him eligible to compete against able-bodied runners.

Pistorius qualified for South Africa's Olympic team in 2012 and competed in the 400-meter race, reaching the semifinals, and the 1,600-meter relay.