Oscar Pistorius: 'I had no intention to kill my girlfriend'

NEW: "I had no intention to kill my girlfriend," Pistorius says in a statement NEW: The track star says in the statement he thought she was a burglar A prosecutor asks why a burglar would lock up in a bathroom Friends and family mourn the death of Reeva Steenkamp at her funeral Tuesday

Pretoria, South Africa (CNN) -- Track star Oscar Pistorius killed his girlfriend accidentally, mistaking her for an intruder in the pitch dark of his home, he told a judge in a statement read by his attorney during his bail hearing Tuesday.

"I fail to understand how I could be charged with murder as I had no intention to kill my girlfriend," Pistorius said in the statement.

Pistorius' attorney read the statement because the runner himself was too distraught to speak. He sobbed and heaved so much during the hearing that the magistrate had to stop proceedings and ask him to compose himself. He broke down each time Reeva Steenkamp's name was mentioned.

In the statement, Pistorius said he awoke in the early hours of the morning February 14 to noises in the bathroom and said a "sense of terror overwhelmed me." He said he thought Steenkamp was in bed beside him and that he was too scared to turn on the lights. He said he shouted to her to call police, but she didn't answer.

He said he was not wearing his prosthetic legs and felt "extremely vulnerable" and needed to protect himself and Steenkamp, 29.

Prosecutors and defense lawyers agree Steenkamp died after being shot by Pistorius, 26. Prosecutor Gerrie Nel said Pistorius shot four times, striking Steenkamp with three bullets.

The Olympic athlete said in his statement that he then carried Steenkamp downstairs. She died in his arms, he said in the statement read by his lawyer.

Prosecutors reject Pistorius' claim that he mistook her for a burglar, saying it would make no sense for an intruder to hide behind a locked bathroom door.

Instead, they say Pistorius armed himself, attached his prosthetic legs and walked 7 meters (23 feet) to shoot Steenkamp through a bathroom door after a heated argument.

Defense attorney Barry Roux questioned the state's argument, asking how prosecutors would know Pistorius had put on his prosthetic legs and walked to the bathroom.

In the emotionally wrenching hearing, the judge upgraded the charge against Pistorius to premeditated murder, saying he could not rule out the possibility that the track star planned Steenkamp's death. But the judge said he will consider downgrading the charge later.

The allegation of premeditation makes it more difficult for Pistorius' attorneys to argue he should be released on bail pending trial. To win bail, the defense must argue that "exceptional circumstances" exist that would justify Pistorius' release.

Pistorius said in the statement read by his lawyer that he will not try to flee or influence any witnesses if he is allowed out on bail.

The hearing ended with prosecutors saying they needed time to study the affidavits read in court before deciding how to proceed. The hearing will resume Wednesday. Pistorius will spend the night at the police station where he's been held since his arrest.

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Final farewells for Steenkamp

As the drama in court unfolded, friends and family mourned Steenkamp at a private funeral in her hometown of Port Elizabeth.

"There's a space missing inside all the people she knew that can't be filled again," her brother Adam Steenkamp told reporters outside.

Steenkamp was a law school graduate whose modeling career was on the rise. She landed the cover of FHM magazine and recently appeared on a reality TV show.

On Sunday, South Africans heard Steenkamp's voice one last time after her death, when the national broadcaster aired a pre-recorded episode of the show. The model talked about her exit from "Tropika Island of Treasure," on which local celebrities compete for prize money.

"I'm going to miss you all so much and I love you very, very much," she said, blowing a kiss to the camera.

Police: Neighbors "heard things earlier"

Authorities have released little information about a possible motive in the shooting.

Items found in Pistorius' home suggest Steenkamp intended to stay the night. She had an overnight bag and her iPad, a South African official familiar with the case said Monday.

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

Authorities said there had been "previous incidents" at the home, including "allegations of a domestic nature," but did not provide details.

Detectives are investigating a blood-stained cricket bat in the home, Johannesburg's City Press newspaper reported, and are trying to determine whether it was used to attack Steenkamp, if she used the bat in self-defense, or if Pistorius used it to try to break down the bathroom door.

Pistorius has rejected the murder allegation "in the strongest terms," his agent said in a statement.

Case rivets fans

The case of the global sports hero known as the "Blade Runner" has riveted stunned fans around the world.

As he walked into court in a blue shirt and gray suit, frenzied photographers snapped away, prompting the judge to demand they stop.

The scene was a far cry from the packed stadiums that erupted in applause whenever the double-amputee competed against men with legs.