PRETORIA, South Africa - Kneeling in court and swinging a cricket bat at Oscar Pistorius' toilet door, a forensic expert demonstrated Wednesday how the double-amputee athlete may have bashed it to get to the girlfriend he had just fatally shot.
Col. J.G. Vermeulen said he believed Pistorius was on his stumps when he swung his bat at the brown cubicle door.
The sprinter is accused of premeditated murder after shooting model and law graduate Reeva Steenkamp through the door early on Valentine's Day last year.
At his bail hearing, Pistorius justified shooting because of the extreme vulnerability he felt due to his disability.
However, in his affidavit Pistorius stated that he had put on his prosthetic legs before smashing down the door.
Vermeulen disagreed.
"The marks on the door are actually consistent with him not having his legs on," he told the court.
Cross-examining the police officer, the defense insisted that Pistorius was wearing his prosthetic legs - and the marks from the bat on the door were lower down because the athlete swung with a bent back.
Vermeulen was repeatedly asked by both the prosecution and defense to demonstrate his assertions by swinging the bat at the door.
The intricate argument over whether the Olympian was on his prosthetic limbs or not is important because it could match parts of his story that he accidentally shot Steenkamp. It could also show that he is lying.
The athlete has said he fearfully approached the bathroom on his stumps on Feb. 14 last year and shot Steenkamp by mistake, thinking she was an intruder hiding behind the door.
According to his account, he then put on his prosthetic legs and tried to kick down the locked toilet door, and battered it with a cricket bat to get to his girlfriend after realizing what he had done.
Prosecutors maintain he intentionally shot Steenkamp, 29. He pleaded not guilty to all charges against him, which also include three firearm related counts.
The actual door that Pistorius shot through a year ago was erected in the Pretoria courtroom Wednesday. The bat he used that night was also used in the dramatic demonstrations. And there was even a toilet cubicle behind the door, recreated to the exact specifications of the small area of Pistorius' bathroom where Steenkamp was fatally shot, Vermeulen said. It included a toilet bowl.
The trial continues.
The Associated Press and Reuters contributed to this report.