Particularly jarring for firearms instructors and legal experts is that Pistorius testified that he shot at a closed toilet door, fearing but not knowing for certain that a nighttime intruder was on the other side. Instead of an intruder, Pistorius' girlfriend Reeva Steenkamp was in the toilet cubicle. Struck by three of four shots that Pistorius fired from a 9 mm pistol, she died within minutes. Prosecutors charged Pistorius with premeditated murder, saying the shooting followed an argument between the two. Pistorius said it was an accident.
South Africa has stringent laws regulating the use of lethal force for self-protection. In order to get a permit to own a firearm, applicants must not only know those rules but must demonstrate proficiency with the weapon and knowledge of its safe handling, making it far tougher to legally own a gun in South Africa than many other countries where a mere background check suffices.
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. Pistorius' license for the 9 mm pistol was issued in September 2010. The Olympic athlete and Paralympic medalist should have known that firing blindly, instead of at a clearly identified target, violates basic gun-handling rules, firearms and legal experts said.
"You can't shoot through a closed door," said Andre Pretorius, president of the Professional Firearm Trainers Council, a regulatory body for South African firearms instructors. "People who own guns and have been through the training, they know that shooting through a door is not going to go through South African law as an accident."
"There is no situation in South Africa that allows a person to shoot at a threat that is not identified," Pretorius added. "Firing multiple shots, it makes it that much worse. ...It could have been a minor - a 15-year-old kid, a 12-year-old kid - breaking in to get food."
The Pistorius family, through Arnold Pistorius, uncle of the runner, has said it is confident that the evidence will prove that Steenkamp's death in the predawn hours of Feb. 14 was "a terrible and tragic accident."
In an affidavit to the magistrate who last Friday freed him on bail, Pistorius said he believed an intruder or intruders had gotten into his US$560,000 (?430,000) two-story house, in a guarded and gated community with walls topped by electrified fencing east of the capital, Pretoria, and were inside the toilet cubicle in his bathroom. Believing he and Steenkamp "would be in grave danger" if they came out, "I fired shots at the toilet door" with the pistol that he slept with under his bed, he testified.
Criminal law experts said that even if the prosecution fails to prove premeditated murder, firing several shots through a closed door could bring a conviction for the lesser but still serious charge of culpable homicide, a South African equivalent of manslaughter covering unintentional deaths through negligence.
Johannesburg attorney Martin Hood, who specializes in firearm law, said South African legislation allows gun owners to use lethal force only if they believe they are facing an immediate, serious and direct attack or threat of attack that could either be deadly or cause grievous injury.
According to Pistorius' own sworn statement read in court, he "did not meet those criteria," said Hood, who is also the spokesman for the South African Gun Owners' Association.
"If he fired through a closed door, there was no threat to him. It's as simple as that," he added. "He can't prove an attack on his life ... In my opinion, at the very least, he is guilty of culpable homicide."
The Associated Press emailed a request for comment to Vuma, a South African reputation management firm hired by the Pistorius family to handle media questions about the shooting.
The firm replied: "Due to the legal sensitivities around the matter, we cannot at this stage answer any of your questions as it might have legal implications for a case that still has to be tried in a court of law." Vuma said on Monday it referred the AP's questions to Pistorius' legal team, which by Tuesday had not replied.
Culpable homicide covers unintentional deaths ranging from accidents with no negligence, like a motorist whose brakes fail, killing another road user, "to where it verges on murder or where it almost becomes intentional," said Hood. Sentences - ranging from fines to prison - are left to courts to determine and are not set by fixed guidelines.
The tough standards for legally acquiring a gun were instituted in part because of a wave of weapons purchases after the end of racist white rule in 1994, said Rick De Caris, a former legal director in the South African police. Under South Africa's white-minority apartheid regime, gun owners often learned how to handle firearms during military service. Many of the new gun owners had little or no firearms training, which brought tragic results, De Caris said.
"People were literally shooting themselves when cleaning a firearm," said De Caris, who helped draft the Firearms Control Act of 2000.
Prospective gun owners must now take written exams that include questions on the law, have to show they can safely handle and shoot a gun and are required to hit a target the size of a glossy magazine in 10 of 10 shots from seven meters (23 feet), said Pretorius of the Professional Firearm Trainers Council.
In his affidavit, Pistorius said he wasn't wearing his prosthetic limbs "and felt extremely vulnerable" after hearing noise from the toilet.
"I grabbed my 9 mm pistol from underneath my bed. On my way to the bathroom, I screamed words to the effect for him/them to get out of my house and for Reeva to phone the police. It was pitch-dark in the bedroom and I thought Reeva was in bed," he testified.
Legal experts said they are puzzled why Pistorius apparently didn't first fire a warning shot to show the supposed intruder he was armed. Also unanswered is why, after he heard noise in his bathroom that includes the toilet cubicle, Pistorius still went toward the bathroom - toward the perceived danger - rather than retreat back into his bedroom.
"He should have tried to get out of the situation," said Hood, the attorney.