Pretoria, South Africa (CNN) -- South African sports icon Oscar Pistorius broke into tears Friday when a judge officially charged him with killing his girlfriend on Valentine's Day.

A grim-faced Pistorius, dressed in a dark suit, shook uncontrollably with his head buried in his hands during the hearing at a packed courtroom in Pretoria.

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Prosecutors say they plan to charge him with premeditated murder.

The athlete rejected the murder allegation "in the strongest terms," his agent, Peet Vanzuyl, told CNN.

 

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<cite class="expCaption">Oscar Pistorius arrives at court</cite>

 

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His girlfriend, model Reeva Steenkamp, was found in a pool of blood at his home Thursday in an upscale neighborhood in the capital.

Neighbors alerted authorities to the early morning shooting, saying they had "heard things earlier," according to Denise Beukes, a police spokeswoman. She did not clarify what the neighbors heard.

The track star was arrested the same day.

READ: Pistorius' girlfriend killed on Valentine's Day she was looking forward to

Local media reported that he had mistaken his girlfriend for an intruder, but the spokeswoman said those reports did not come from authorities.

There was no evidence of forced entry at the home, she said.

Police gave no motive for the fatal shooting, but said there had been previous "allegations of a domestic nature" at his house. They did not provide details.

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A pistol was recovered at the scene, police said.

South Africa has a high crime rate, and many homeowners keep weapons to ward off intruders.

"There are 1.5 million gun owners -- about 3.5 million guns in civilians hands," said Alan Storey, chairman of Gun Free South Africa.

Most of the victims of gun homicides are between the ages 20 and 30, according to Storey, who said such deaths are rampant in the nation of about 50 million.

"This tragedy is not more important than others, it is just because of the people involved," he said.

Storey said the nation has tough legislation that includes a requirement for a thorough background check for prospective gun owners. The check includes spouses and partners, and is repeated every few years, he said.

WATCH: Police probe shooting at Pistorius home

"People acquire guns believing they are more safe ... but they place themselves at great risk," Storey said. "We've made airplanes a gun-free zone. We need to bring that logic down to earth."

But the South African Gunowners' Association, a popular gun lobby group, has said citizens have the right to protect themselves from increasingly violent crimes.

"There are already more than enough laws and regulations to control the possession of firearms by private citizens," it says on its website. "Fewer and less complex laws reasonably, yet properly, applied could achieve the required objective."

 

<cite class="expCaption">See inside Pistorius' home</cite>

From hero to murder suspect

As the shocking allegations reverberated worldwide, stunned South Africans grappled with the news of their fallen hero.

When Pistorius was a toddler, his legs were amputated below the knees because of a bone defect, and he runs on special carbon fiber blades. He became the first Paralympic sprinter competing against able-bodied athletes at the London Olympics last year.