The trial of Oscar Pistorius begins in Pretoria, South Africa with the Olympic and Paralympic track star pleading not guilty to murdering his girlfriend, Reeva Steenkamp. (Reuters)

Olympian Oscar Pistorius goes on trial for murder Monday for the 2012 slaying of his girlfriend.

The double-amputee runner says he thought Reeva Steenkamp was a nighttime intruder, shooting her through the bathroom door in his home in the early hours of Feb. 14, 2013. The prosecution maintains that he intentionally shot her several times after an argument.

The trial, which has some parallels with the O.J. Simpson case in the United States 20 years ago because of the celebrity factor, the sensational allegations and the fascination of people around the world. But there is one glaring difference: Pistorius acknowledges that he killed Steenkamp.

Although Pistorius, who became the first double-leg amputee to run in the Olympics during the 2012 Games in London, may be acquitted for murder, he may still be convicted of homicide under South Africa’s strict gun laws.

“Any person that has admitted to killing another person in circumstances when your actions are unlawful will face a steep hurdle in getting off scot-free,” said Marius du Toit, a former prosecutor, magistrate and now criminal defense lawyer.

Graphic: What “Blade Runner” Olympian says happened the night he shot his girlfriend

In order to get a permit to own a firearm in South Africa, applicants must not only know those rules but must demonstrate proficiency with the weapon and knowledge of its safe handling.

Pistorius took such a competency test for his 9 mm pistol and passed it, according to the South African Police Service’s National Firearms Center. He therefore should have known that firing through a closed door cannot be viewed in South African law as an accident, according to Andre Pretorius, president of the Professional Firearm Trainers Council, a regulatory body for South African firearms instructors.

Criminal law experts say that if the prosecution fails to prove premeditated murder, firing several shots through a closed door could bring a conviction for the lesser charge of culpable homicide, a South African equivalent of manslaughter, which could still land him in prison.

— Associated Press