A ballistics expert called by Pistorius' defense at his murder trial testified that Reeva Steenkamp was falling back in a toilet cubicle in the double-amputee athlete's home when she was hit in the head by the last of the four bullets Pistorius fired through the cubicle door.
"She was not sitting yet when the last shot was fired," expert Wollie Wolmarans testified.
Wolmarans' testimony contradicted evidence given by the prosecution's police ballistics expert who said Steenkamp was sitting on a magazine rack and desperately protecting her head with her arms when the last shot struck her.
Both sides say the first shot likely hit Steenkamp in the right hip as she was standing behind the door, causing her to fall.
The painstaking debate over detail reflects the defense's efforts to show that Steenkamp was not arguing with Pistorius after fleeing from him when she was shot in the predawn hours of Feb. 14, 2013 -- as the prosecution contends.
Pistorius, 27, is charged with premeditated murder for Steenkamp's shooting death. He says the killing was accidental because he mistook her for a dangerous intruder about to come out of the cubicle and attack him. The runner held his thumbs in his ears at times in the courtroom when Wolmarans talked about Steenkamp's fatal wounds.
Wolmarans, who was testifying for the second day at Pistorius' trial, also said it was his opinion that the four shots were fired in "fast succession," apparently supporting Pistorius' contention that he shot rapidly and in panic after thinking there was an intruder in the cubicle.
The prosecution believes there could have been a gap between the first and the following three shots, arguing Pistorius fired with deliberate intent to kill.
Prosecutor Gerrie Nel argued that Wolmarans' opinion about Steenkamp's position when she suffered some of the gunshot wounds didn't make sense, with Nel citing the small size of the toilet cubicle and blood and tissue spatter on a wall and the toilet lid.
Before beginning his cross-examination, Nel invited the judge and her two assessors to leave their seats and take a closer look at a reconstruction of the toilet cubicle that has stood in the courtroom for much of the trial, and where the prosecution had prepared a display Friday.
The judge was led by the hand through the courtroom by a police officer before the police's ballistics expert sprayed a substance into the reconstructed cubicle. Red laser beams became visible in the exhibit to show possible bullet trajectories. Judge Thokozile Masipa, dressed in her traditional red robe, pointed with her finger into the cubicle at one point and appeared to ask Nel a question.
Judge Masipa will deliver a verdict because South Africa does not have trial by jury. Pistorius faces 25 years to life in prison if convicted on the premeditated murder charge.
Information from The Associated Press was used in this report.