Paralympic and Olympic track athlete Oscar Pistorius has been charged with murder after he allegedly shot and killed his 30-year-old model girlfriend on Thursday morning. The South African sprinter—who lost both his lower legs due to congenital birth defect and runs with the aid of prosthetics—was arrested in his hometown of Pretoria and is set to appear in court today Friday. Police had initially said Pistorious would be in court on Thursday.

That today is Valentine's day puts a macabre sheen on the murder charge, but police are still trying to figure out exactly what happened. There are unconfirmed reports that Reeva Steenkamp, Pistorius's girlfriend, was trying to surprise him and he mistook her for an intruder. However, police told Sky News that this report did not come from them and the AFP is reporting that the couple have had domestic disputes in the past: 

What we do know is that Steenkamp was shot four times in the head and upper body and that police have launched an investigation as if it was homicide. "The deceased was shot four times and died on the scene. It is believed that she was the girlfriend of the accused," police spokesman Katlego Mogale is quoted as saying in the Sky News report. The AP adds that the South African Police Association will oppose bail, and the BBC adds that police said there are other witnesses to the shooting. 

Pistorius, who made a name for himself this past Olympic Games as the "Blade Runner," is expected to appear at Pretoria Magistrate's Court later this afternoon.