Fast Cars, Hot Temper, Guns: Finding the Real Oscar Pistorius

Friends and a journalist describe the private life of the hero turned killer.

March 1, 2013— -- Today in South Africa, Oscar Pistorius' lawyers are trying to reach a settlement with a woman who accused him of assault and called the police. Pistorius sued her for libel, saying the short time he spent in jail ruined his reputation and caused him to lose endorsement deals -- even though no assault charges were ever filed.

Watch the full story on "20/20: The Fast Times of Oscar Pistorius" TONIGHT at 10 ET

"It's such a compelling, heart-warming story of a young man putting those carbon fiber blades on -- there were millions of people with disabilities around the world who [thought], 'I'm going to cheer for him. I could be him," said Christine Brennan, a sports columnist and commentator for ABC News.

"The reality is, it's nothing of the sort," Brennan continued. "We have no idea who Oscar Pistorius is except for that brief time that he is on the track in front of us."

Full Coverage: Oscar Pistorius Case

What we are finding out is surprising. Behind the inspirational athlete lurks a different figure, living a fast life: fast cars, dirt bikes, pet tigers and a passion for weapons.

"He was into the fast life, the fast car," said David O'Sullivan, a South African radio personality and friend of Pistorius . "He was about to buy himself a supercar, a McLaren."

"Oscar was more than a little crazy. Mainly because of the way he drove," said Michael Sokolove, a sports writer for the New York Times. Sokolove visited Pistorius in South Africa in 2011 and found that for the young star, the need for speed extended beyond the track to macho pursuits like power bikes and sports cars. And, as he did with his own body, Pistorius liked to push those machines to their limits.

"We were driving 150 miles an hour," Sokolove said. "There was a point that it was raining. We were on some state's turnpike, and he's weaving in between cars and tailgating them. And just really insane driving. He saw it as sport. But I feared he would hurt himself."

Pistorius did wipe out on his dirt bike, resulting in a darkly comic moment, Sokolove said.

"One of his artificial legs came off. It was hanging on a fence post. And he just joked. He said, 'Well, I guess that was one time when it was an advantage not to have your own leg.'"

Another accident was less funny.

In 2009 Pistorius came within inches of his life after he hit a submerged pier in a speedboat accident on the Vaal River, in South Africa. He smashed his eye socket, jaw, nose and two ribs, and needed to be airlifted to a hospital for special surgery.

"I remembered talking to him afterwards," O'Sullivan said, "and he said it made him take stock of his life and realize, 'Well I can't behave in that way.' And I thought, Well, there's Oscar's wake-up call."

Pistorius tried to slow down, but the flirting with danger -- and beautiful women -- never stopped. He invested in race horses, kept two pet tigers and maintained a strong interest in weaponry.

"He'd say, 'Well, I'm sort of antsy, I can't sleep. Let's go to the shooting range,'" Sokolove said. "I thought that was somewhat bizarre then, and in the light of day, more bizarre now."

Pistorius owned multiple guns, and it wasn't just for sport. Pistorius had legitimate concerns about safety, given the violence in South African society.

Pistorius reportedly slept with a gun by his bed, and in a recent tweet he recounted nearly shooting up his own washing machine when he mistook its noise for the sound of an intruder.

Pistorius' friend Kevin Lerena has his own story to tell, from a night at a Johannesburg restaurant.

The Real Oscar Pistorius

"Oz happened to ask my one mate to see his gun. My mate passed the gun across to him and unfortunately the gun went off. The bullet missed my toe by an inch. I could have lost my foot," Lerena said.

"I've never seen a person's face change so quickly in my life," Lerena went on. "[Pistorius] went pale; he actually started shaking he was so apologetic."

Even freak accidents can be bad for one's image, so the incident was covered up.

"My friend took the fall for [Pistorius] because of his status," Lerena told "Good Morning America." "No one was saying 'protecting Oscar,' but someone else took the fall for us as a friend."

Clearly the "Blade Runner" was a hot-blooded alpha male -- but was he also hot-tempered? Last year, after a series of jealous texts over an 18-year-old girlfriend, police say, Pistorius told another man he would break his legs.

"I was amazed," O'Sullivan said. "I was taken aback. I didn't think Oscar had it in him to make those kinds of threats, to threaten that level of violence."

"He's got his moments of anger," O'Sullivan continued. "Maybe too many people wanting too much from him, and eventually he snaps. ... I could never say these are premonitions of greater darkness to Oscar's personality, though."

"His P.R. machine was very good and covered up his few indiscretions," said Andy Grudko, former South African reserve police officer.

Whatever human shortcomings Pistorius may have had, the image the public wanted to preserve was London 2012, his sprint into immortality as the first double-amputee Olympian.

But weeks later, the Paralympics were held in the same stadium. After a surprising upset, Pistorius' good sportsmanship went out the window. He said that the Brazilian sprinter who beat him at the finish line had an unfair advantage because of his running blades.

"He said it was unfair, and he was petulant about it, and this shocked people," Michael Sokolove said. "He apologized, he said he regretted it. Everybody looks back now: Was this something that changed him, or was this evidence that he had already changed?"

This fall Pistorius told friends that his life had changed -- for the better. That was when he met the gorgeous girl from Port Elizabeth, Reeva Steenkamp.

Friends have testified that Pistorius was deeply committed to the relationship. If anything, they said, his heart was racing faster than Steenkamp might have wanted.

Amid the exhilaration of new love, Valentine's Day was going to be special: flowers, dinner and romantic plans. Reeva Steenkamp's last tweet read, "what do you have up your sleeve for your love tomorrow??? #getexcited#valentinesday"

Watch the full story on "20/20: The Fast Times of Oscar Pistorius" TONIGHT at 10 ET