LAWYERS for Paralympian Oscar Pistoriusfor a second day on Tuesday grilled a key witness at his murder trial who claims to have heard screams, then shots, as his girlfriend was killed.
The second day of Pistorius's trial for the Valentine's Day killing of Reeva Steenkamp began with lawyer Barry Roux redoubling efforts to pick apart the prosecution's premier witness.
Neighbour Michelle Burger testified Monday that she heard "bloodcurdling" screams at the home less than 200 metres (yards) away from her own, before shots rang out in the early hours of February 14, 2013.
The sequence of events, if accurate, would undermine the Paralympic gold medallist's claim that he shot Steenkamp after mistaking her for an intruder.
Pistorius, 27, a double amputee known as the "Blade Runner" for his carbon-fibre running blades, pleaded not guilty to murder and three unrelated gun charges on the opening day of the trial.
In a statement read out by his lawyer Kenny Oldwage, the sprinter described Steenkamp's death as a "tragic accident".
While admitting killing the 29-year-old model and law graduate, he denied murderous intent.
"This allegation is denied in the strongest terms," he said. "We were in a loving relationship."
If found guilty of premeditated murder, Pistorius faces 25 years in South Africa's notoriously brutal jails and an abrupt end to his glittering sporting career.
Arriving at court on Tuesday, a tired looking Pistorius -- carrying an umbrella and a briefcase -- immediately greeted his lawyer then shook the hand of a police officer. When seated he began to pray.
- 'Bang... bang, bang, bang' -
Monday's proceedings were dominated by the duel between Roux and Burger -- who is a construction economics lecturer at the University of Pretoria.
Burger, the first prosecution witness, said she and her husband were awoken at around 3:00 am by "bloodcurdling screams" coming from the Pistorius home in an upmarket gated community of Pretoria.
"She screamed terribly and she yelled for help," Burger recalled. "It was something you can't explain to someone else, how anxious those screams were."
"Just after her screams, I heard shots, four shots," she said, describing one clear shot then three clustered together.
"Bang... bang, bang, bang."
"I heard petrified screaming before the gunshots, and just after the gunshots," she said when pressed by Pistorius's lawyer.
Roux grilled her over the number of shots she heard -- and whether they were gunshots at all -- suggesting that Burger's account contradicted that of her husband, who has yet to testify.
Roux also suggested she may have mistaken for shots the sound of Pistoriusbreaking the toilet door with a cricket bat after realising that Steenkamp was inside.
Roux also questioned Burger's claim that she heard the shouts of both a man and a woman.
"You know... if Mr Pistorius is very anxious, if he screams it sounds like a woman's voice," Roux said.
Criminal law advocate Dave Smith, who is not linked to the case, told AFP that Burger "looks solid as a rock" in the witness stand.
"It's important to prove her wrong but I don't think he will," he said. "I'm happy I'm not him."
"She is firm that she heard screams, then gunshots and that they weren't the sound of a cricket bat. That says it all."
- Botched evidence -
As well as relentlessly picking holes in the testimony of state witnesses, the defence is also expected to call into question the reliability of the prosecution's forensics.
Pistorius walked free on bail a year ago as the chief detective on the case and the prosecution's star witness Hilton Botha was sacked amid a scandal over botched handling of evidence.
A single judge, Thokozile Masipa -- aided by two assistants -- will rule in the case, which has already been likened to the murder trial of American footballer OJ Simpson over the killing of his ex-wife and a friend in 1995.
The trial is expected to last three weeks.
PISTORIUS TRIAL: Key witness grilled