In the eighth day of the Oscar Pistorius murder trial, a veteran forensic investigator testified he believed that the double-amputee Olympian was on his stumps when he fired his gun; and later, personally hacked away at the door the runner bashed through with girlfriend Reeva Steenkamp lying dead on the other side.

Col. J.G. Vermeulen on Wednesday, taking the stand in South Africa's Pretoria Magistrate's Court, said "the marks on the door are consistent with him being in a natural position without his prostheses."

At one point, Vermeulen got on his knees and physically mimicked Pistorius' possible chain of actions after he shot through the bathroom door, then used a cricket bat to smash it open. Both the actual door -- riddled with bullet holes -- and bat were brought into the court for the demonstration.

Pistorius' lawyer Barry Roux said that the paralympian had his prosthetics on, and his back bent, at the time he hit the door. (The issue over the prosthetics ties into Pistorius' story regarding what he claims was an accidental shooting; as well as a gauge of how honest he's been regarding the incident.)