A beloved model is dead, those who knew her are in mourning, and one of the world's most admired Olympians is charged with her murder after a Valentine's Day shooting in South Africa.

Oscar Pistorius, a Paralympic runner who blazed new terrain by competing in last summer's Olympics, is accused of killing his girlfriend, Reeva Steenkamp. A shooting took place inside his upscale home in Pretoria, South Africa, early Thursday, and only the two of them were there at the time, police said.

Shock waves from the incident quickly reverberated across the world, casting a shadow over the man known as the "Blade Runner" for his achievements on prosthetic limbs.

Pistorius will be named officially as the suspect when he appears in court Friday, in keeping with South African law. Authorities have already announced that the suspect is Pistorius' age.

Investigators gave no motive for the alleged killing.

"Previous incidents" at the home, police say

Police were alerted to the shooting by neighbors, and residents had "heard things earlier," spokeswoman Denise Beukes said.

A police spokeswoman said there had been "previous incidents" at the home, including "allegations of a domestic nature." They did not detail what those may be.

Pistorius was arrested and accused of common assault in 2009, but the case was thrown out because of a lack of evidence, police told CNN on Thursday.

That incident involved Pistorius allegedly slamming a door during a party, and a piece of the door fell off and hit someone, said Capt. Marissa Van der Merwe of South African police.

Police are not aware of any prior incidents between Pistorius and Steenkamp, Van der Merwe said.

Some South African media outlets suggested Pistorius may have mistaken Steenkamp for an intruder. South Africa has a high crime rate, and many homeowners keep weapons to ward off intruders.

Beukes said those reports did not come from police. There did not appear to be signs of forced entry at the home, she added.

"This is a very quiet area, and this is a secure estate," Beukes said.

A pistol was recovered at the scene, police said.

In November 2011, Pistorius tweeted a photo of himself at a gun range, and wrote that he had "a 96% headshot over 300m from 50 shots! Bam!"

Pistorius cooperating with police

Pistorius has made no public statement. His spokeswoman Kate Silvers said the athlete is "assisting the police with their investigation but there will be no further comment until matters become clearer later today." Police also said Pistorius is cooperating.

He arrived Thursday at a police station in Pretoria.

Beukes said the state will oppose bail. That means the 26-year-old, who was among the men featured in People magazine's "Sexiest Man Alive" issue, could be behind bars, at least temporarily.

Pistorius is not being brought to court Thursday because the public prosecutor needs more time to prepare the case, police spokeswoman Katlego Mogale told CNN.

A model's life violently cut short

Steenkamp, 29, had been looking forward to Valentine's Day, encouraging her Twitter followers to "get excited" for the holiday.

On Wednesday, she tweeted, "It's a beautiful day! Make things happen. Starting my day off with a yummy healthy shake from my boo," followed by a smiley face. "Boo" is a term for boyfriend.

"She was the kindest, sweetest human being; an angel on earth and will be sorely missed," Capacity Relations, the agency that represented her, wrote on Twitter.