Defence lawyers of South African athlete Oscar Pistorius are to resume questioning a neighbour who told a court in Pretoria that heard a woman’s “terrible screams” on 14 February 2013.
Mr Pistorius has pleaded not guilty at the start of his trial for the murder of his girlfriend Reeva Steenkamp.
He shot dead the 29-year-old model and reality TV star at his home, saying he mistook her for an intruder.
The neighbour, Michelle Burger, said cries for help were followed by shots.
“She screamed terribly and she yelled for help. Then I also heard a man screaming for help. Three times he yelled for help,” Ms Burger told the high court in the capital.
She said she called security and then heard four gunshots.
The arrest of the national sporting hero astounded South Africa.
The 27-year-old double amputee won gold at the London 2012 Paralympic Games and also competed at the Olympics.
For the first time in South Africa, parts of the trial are being televised live, although Ms Burger’s testimony, in Afrikaans, was only relayed in audio.
Reporting from the courtroom on Monday, the BBC’s Andrew Harding said Mr Pistorius looked calm, or at least neutral as he arrived – a far cry from the emotional wreck he seemed at the bail hearing last year.
Mr Pistorius pleaded not guilty to all charges, including the “wilful and intentional murder of Reeva Steenkamp” as the trial began.
His lawyer read out a statement from the athlete, giving his version of events of how Ms Steenkamp died, saying he believed his girlfriend was in bed when he shot at the toilet door in the early hours of Valentine’s Day last year.
Ms Burger told the court she lived nearby on a neighbouring gated estate to Mr Pistorius in Pretoria – and she and her husband were sleeping with the windows open.
“It was very traumatic for me. You could hear blood curdling screams,” she said.
Defence lawyer Barry Roux questioned Ms Burger over differences between her sworn statement and her testimony.
State prosecutors say Mr Pistorius planned the killing and shot Ms Steenkamp after a row.
If found guilty of premeditated murder, he could face life imprisonment.
He has also been charged with illegally possessing ammunition.
There are no juries at trials in South Africa, and his fate will ultimately be decided by Judge Thokozile Masipa.
Much of the case will depend on ballistic evidence from the scene of the shooting, correspondents say.
On the anniversary of the shooting, Mr Pistorius released a rare statement in which he said: “The loss of Reeva and the complete trauma of that day, I will carry with me for the rest of my life.”