The Blade Runner, he was called by his nickname over the public-address system. The first double-amputee runner to compete in the Olympics. A man who overcame tremendous odds after being born in South Africa with no fibula bones in his lower legs, which were surgically removed below the knee when he was 11 months old.
And then Pistorius launched out of the starting blocks in the opening heats of the 400 meters, advancing to the semifinals, serving as an inspiration to many, continuing to blur the lines between abled and disabled.
"If something like that happens to you and you lose both legs, some people would give up," Bryshon Nellum, a quarter-miler from the US, said after the race. "For him to continue to run, it's unbelievable. It's amazing."
Yet both Pistorius' career and his personal life were complicated. In the world of track and field, he was inspiring and polarizing. Even as he ran in the Olympics, the debate continued about whether his carbon-fiber blades gave him an unfair advantage over other runners.
No less a figure than Michael Johnson, the retired world-record holder and two-time Olympic champion at 400 meters, said Pistorius, while a friend and a great ambassador, should not compete at the London Games.
"Because we don't know for sure whether he gets an advantage from the prosthetics that he wears, it is unfair to the able-bodied competitors," Johnson said.
Half a year later, on Valentine's Day, Pistorius, 26, was accused of shooting to death his girlfriend, Reeva Steenkamp, 29, a model and law school graduate. And we are reminded yet again that it becomes risky to equate sporting accomplishment with heroism and incorruptible behaviour.
Sport builds characters, sure, but does it really build character? How can we really expect to know these athletes, when they often give us a kind of fan dance - suggesting but not fully revealing.
Pistorius certainly had a stirring and galvanizing story to tell. At the London Games, he recounted a letter his mother Sheila, who died when he was 15, had written to him: "A loser isn't the person that gets involved and comes last, but it's the person that doesn't get involved in the first place."
Pistorius said: "It's a mentality we've always had. When you start something, you do it properly."
But his story was also a knotty one. A need for speed captivated Pistorius off the track as well as on. He liked fast cars and fast motorcycles and fast boats, and sometimes he veered toward recklessness.
In 2009, he wrecked a speedboat into a submerged pier along a South African river. The police said they found alcohol in the boat but did not immediately check Pistorius' blood-alcohol level. He slammed into the steering wheel and fractured two ribs, his jaw and an eye socket. Doctors needed 172 stitches to repair his handsome face.
In a profile last year in The New York Times Sunday Magazine, Michael Sokolove wrote of Pistorius' risk-taking and described him as "a great deal of fun" and "more than a little crazy."
The night before the interview with Sokolove, Pistorius said that his security alarm had sounded and that he grabbed a gun to check on a possible intruder. (South Africa is one of the world's most violent countries.) This time, there was nothing. Pistorius then took Sokolove to a shooting range with a 9-mm handgun, saying he went there "just sometimes when I can't sleep."
On November 28, 2011, Pistorius bragged on his Twitter account about his accuracy with a weapon: "Had a 96(PERCENT) headshot over 300m from 50shots! Bam!"
Those who support Pistorius are now left to hope for an awful consolation: that he shot his girlfriend not on purpose but by accident in an apprehensive, armored country, where many fear home invasions and live barricaded in houses surrounded by high fences topped with barbed wire.
Jonathan McEvoy, a reporter for The Daily Mail of London, visited Pistorius in 2011 at his home in Pretoria. On Thursday he wrote, "In Oscar's bedroom lay one cricket bat and one baseball bat behind the door, a revolver by his bed and a machine gun by the window."
But Pistorius has been charged with deliberate murder, not an inadvertent shooting. The South African police said they were surprised to hear news accounts that Pistorius had offered an intruder defense. They also said there had been previous complaints of a "domestic nature" at his home.
Late last year, according to South African news media reports, he reportedly threatened to break a man's legs in an incident involving another woman.
Those who had met Pistorius were left Thursday to deal with the shuddering contradiction between the runner as brave competitor and possible murderer. Steven Ungerleider, a sports psychologist from Eugene, Ore., who works with Olympic athletes and has spoken twice with Pistorius in friendly conversation, said he was "shocked, horrified."
"What I got was that he liked to push the edge, like all great athletes, but I didn't get the feeling that he was an outrageous guy, out of control, taking unnecessary risks," Ungerleider said. "He never came across as arrogant."
"Sometimes," Ungerleider continued, "you think you kind of know where people are, then all of a sudden that perception goes. I'm just shocked and sad."