Oscar Pistorius' Murder Trial Just Began

On Monday, former Olympic champion Oscar Pistorius began his murder trial, pleading not guilty to the murder of his supermodel girlfriend, Reeva Steenkamp. Although the South African runner, who become the first amputee to take home a medal in an able-bodied track race back in 2011, has admitted to shooting his girlfriend on February 14th of last year — yup, Valentine's Day — he's sworn it was by mistake.

The first witness to be called to testify was a neighbor of Pistorius', Michelle Burger, who claims she was woken up by the sound of Steenkamp's screams early on Feb. 14 last year. “It was a very traumatic thing. We could hear very close, bloodcurdling screams,” she told the court. “Something terrible was happening at that house."

How did Pistorius go from history-making Olympic champion to murder defendant? Here's a timeline...

August-September 2012

Oscar Pistorius, who underwent double amputation of both legs below the knee at eleven months old, makes history by becoming the first runner with his disability to compete at the London Olympics in August 2012.

He takes home the silver at the London Paralympic Games for the 200-meter race in September, immediately shoots to fame and glory, and becomes a South African hero.

February 2013

Pistorius's fame takes a gruesome turn: He's arrested early on the morning of Valentine's Day after fatally shooting his supermodel girlfriend, Reeva Steenkamp, at his home in Pretoria, South Africa. Pistorius is formally charged with murder a few days later.

According to the prosecution team, Steenkamp died of three bullet wounds, allegedly shot through the bathroom door, after a fight with the Olympian. Pistorius' defense team has argued that Pistorius thought Steenkamp was an intruder.

August 2013

The embattled runner is indicted on charges of premeditated murder, and prosecutors promise to push for a 25-year prison sentence. Pistorius is also charged with illegally possessing ammunition, and his court date is set for March 3 (today.)

February 2014

Pistorius posts a (twisted? Sweet? Your call) message on his website on his website on Valentine's Day 2014, the anniversary of Steenkamp's death.

He writes: "No words can adequately capture my feelings about the devastating accident that has caused such heartache for everyone who truly loved – and continues to love Reeva."

March 2014

On Monday, March 3, Pistorius pleads not guilty of the intentional killing of Steenkamp. As his trial opens in the Gauteng High Court amid a media frenzy.

“My husband went back on the balcony. I was still in bed. I heard her scream again. It was worse. It was more intense. She was very scared. The screams were at a climax,” she continued.

The next day, Burger went on, her husband told her Pistorius had been arrested and had told police he'd thought Preeva was a burglar. Burger said she didn't believe it. “I told my husband it could not be, because that was not what we heard."

Since there aren't any juries in South African trials, it's all up to Judge Thokozile Masipa to decide the outcome of the case.