Oscar Pistorius Enraged When Cop Touched His Gun Darren Fresco testifies against his friend in murder trial.

PRETORIA, South Africa, March 11, 2014 -- One of Oscar Pistorius' friends testified in court today how the Blade Runner yelled at a police officer at a traffic stop for touching Pistorius' gun and angrily told the cop that he would liable if anything happened with the weapon because the officer's fingerprints were now on the gun.

After driving away from the police Pistorius surprised the driver by firing the gun through the car's sunroof.

The testimony by Darren Fresco at Pistorius' murder trial was apparently meant to demonstrate that Pistorius had a bad temper and liked guns.

Pistorius, 27, is on trial for the alleged murder of his model girlfriend Reeva Steenkamp. He could face at least 25 years in prison if convicted of murder.

Oscar Pistorius' Murder Trial in Pictures

The court also heard testimony from the pathologist who did the autopsy on Steenkamp and his testimony raised questions about Pistorius' version of what happened that night.

Fresco told the court about an incident in 2012 in which he, Pistorius and Pistorius' ex-girlfriend Samantha Taylor were pulled over for speeding. Fresco said one of the police officers picked up Pistorius’ gun from the car seat. "And because it was ‘one up,’ [a round in the chamber] the officer cleared it, causing the bullet in the chamber to be ejected into the car.”

The officer's actions angered Pistorius, Fresco said.

"You can't just touch another man's gun," Pistorius told the officer, Fresco testified.

The court heard that Pistorius screamed at the policeman, “Your fingerprints are now all over my gun, so if something happens, you will be held liable."

After driving away from the traffic stop, Pistorius fired the gun through the car's sunroof.

"Without prior warning, he shot out of the sunroof. I flinched ... It was right next to my ear. I asked him, 'Are you f****** mad?’ He just laughed," Fresco testified.

Taylor testified about this same incident when she took the stand last week. But in contrast to her evidence, in which she said that Pistorius and Fresco talked about shooting out a traffic light, Fresco said the shot took him completely by surprise.

While these discrepancies might seem insignificant, the defense has already latched on to them to try and paint Fresco as an unreliable witness.

Fresco also told the court that Pistorius once asked him to take the blame when Pistorius dropped a gun that Fresco has passed to him under a table in a restaurant. The gun discharged when it was dropped.

Earlier, pathologist Dr. Gert Saayman estimated the food found in Steenkamp’s stomach during the autopsy was eaten two hours before her death. The doctor’s testimony conflicted with the account Pistorius gave in his bail application of the night he shot Steenkamp.

Pistorius had said he was in bed at 10 p.m. while Steenkamp did yoga in his bedroom. In his version of events, he also states that, “After Reeva finished her yoga exercises she got into bed and we both fell asleep.”

Other testimony by neighbors has described hearing an argument in the hours before Steenkamp was shot.