JOHANNESBURG — His head shrouded by a sports hoodie, the young man walked unnoticed through a bustling crowd outside the gates of the Olympic village in London last year. When he got close, I saw a familiar face smiling at me.

It was Oscar Pistorius. "Gerald!" he called and then raised both hands for a double high-five greeting followed by a hug.

On Feb. 14, I saw Pistorius in a hood again, and this time he stared straight at the ground, hands thrust into the pockets of a gray sports jacket. He was flanked by officers as he left a police station. Hours earlier, he'd been charged with killing his girlfriend.

It is hard to reconcile the easygoing, charismatic man I interviewed on several occasions with the man accused of premeditated murder in the shooting of Reeva Steenkamp in his South African home. Prosecutors painted him as a man prone to anger and violence, though he had no prior criminal record. The Olympian says he shot Steenkamp by mistake, thinking she was a nighttime intruder, while prosecutors allege he intentionally shot her after the couple argued.

Who is Oscar Pistorius? I thought I had some idea, and in a sense, so did the millions around the world who cheered the double-amputee athlete as a symbol of determination over adversity.

Now he is as much of a mystery as whatever happened in his home in the early hours of Valentine's Day.

My meeting with Pistorius in London was one of several in the three years I have been covering his remarkable story for The Associated Press, from South Africa to Italy to London — and last week to Courtroom C on the first floor of the red-bricked and gray-walled Pretoria Magistrate's Court in the South African capital.

On reflection, Pistorius' narrative is partly an exploration of how hard it is to truly know someone who lives so much in the public eye. Journalists witnessed or heard reports of occasional flashes of anger — with hindsight, do they loom as potentially more meaningful? At the time the outbursts passed largely unnoticed.

What I do know is that the public Pistorius seemed to have a soft spot.

Weeks before his debut at the Olympics, he stopped an interview with me to talk to a little girl who walked up to give him a strawberry from the gardens of the rural hotel at his training base in Gemona, in northern Italy.

"Oscar, Oscar," the little girl said, holding out the berry. Behind her, a woman called the child away to stop her from bothering Pistorius.

"Ciao, baba. Grazie," Pistorius replied with a smile, unfazed by the interruption, showing off his Italian and pretending to eat the strawberry.

"She brings me something to eat every night," he told me delightedly, pointing up to the windows of his hotel room.

Now the world knows Pistorius owns a 9 mm Parabellum pistol, licensed for self-defense, and that he applied for licenses to own six more guns — listed for his private collection — weeks before the shooting death of Steenkamp.

His relationships with women have been spread over the gossip pages in South Africa.

We spoke about his running, his love of sneakers and nice clothes but also about his history with fast cars and motorbikes and the high-speed boat crash in 2009 that left him in a serious condition in the hospital with head wounds. He conceded that the crash caused him to rethink how he lived.

"I just realized that I need to make some changes and some of them need to be with my lifestyle," Pistorius told me last year in that interview in northern Italy. "I was messing around a lot with motorbikes and just playing around and taking unnecessary risks."

Again with hindsight, was he grappling with anything deeper than just the high spirits and penchant for thrills of many young men flushed with success and money to burn?

Covering Pistorius' track career, he became more comfortable with me, remembering my name and shouting it when he would see me among a pack of journalists.

During his Olympic preparations in Italy, Pistorius pulled out his cellphone to show me pictures of his bleeding leg stumps, rubbed raw from the friction of pounding around the track on his blades.

It was around the time when people were again questioning whether he should be allowed to run in the 400 meters against able-bodied athletes. The message in showing these graphic photos was: Do you still think I have an unfair advantage?

Until that moment, I hadn't fully realized what Pistorius went through every time he slipped on his prosthetic blades to compete or train. Not many people had, I guess.

It was rare for Pistorius to show images of his amputated limbs, but he grinned and shrugged. He said it was just part of the job.

It took a long time for him to get used to people filming and taking photographs of him putting on his carbon-fiber blades. He used to ask people not to film him without his prosthetics.

When he finished a race at the South African national championships last year, he quickly disappeared to a secluded part of the track to swap his blades for artificial legs, complete with sponsored sneakers that his agent was holding for him. It was his regular post-race routine. He then came bounding back to give me an interview.

He often apologized when he had to end an interview because he was running out of time. It always seemed people wanted more of his time than he could give. After we talked in London, Pistorius stayed a little longer to pose for photographs with Olympic security staff, even convincing one shy lady to get into one of the pictures.

Then he popped on his identity-concealing hood and, on his prosthetic legs, he walked off, anonymous in the crowd.