Pretoria, South Africa (CNN) -- Sounds of arguing for an hour before the shooting. Blood stains on a cell phone and cricket bat. Boxes of testosterone and needles. Angles of gunfire.
The shape of prosecutors' case against Oscar Pistorius began to come into focus Wednesday as they argued the Olympian charged with killing his girlfriend is a flight risk who should be denied bail.
Police investigator Hilton Botha told the court there's no way Pistorius was acting in self-defense when he shot through the door of a toilet room in the bathroom of his home and killed Reeva Steenkamp.
Pistorius has said he thought he was shooting at an intruder in the early hours of Valentine's Day, but Botha said he believes Pistorius knew Steenkamp was on the other side of the door.
Prosecutors tried to poke holes in Pistorius' story, and defense lawyers fired back:
The witness who heard sounds of arguing lives 600 meters (more than 650 yards) away, Botha testified under cross-examination. Pistorius had a legal herbal medicine, not testosterone, defense attorney Barry Roux said. Steenkamp locked the toilet room door when she heard Pistorius screaming for help, Roux said.
Pistorius is charged with premeditated murder in the killing of his girlfriend. The hearing will determine if he can be released on bail.
Prosecutors set the scene in the bathroom as Botha said investigators found a firearm on the bathroom mat and two cell phones in the bathroom; neither phone had been used to make a call. There was blood on one of the phones.
Botha said police believe a blood-splattered cricket bat found in the bathroom was used to break down the locked door to the toilet; part of the door was lying in the bathroom.
The defense argued that Steenkamp locked the toilet room door when she heard Pistorius screaming for help, something he said in his affidavit a day earlier. Roux also said her bladder was empty, which was consistent with going to the bathroom.
Botha agreed with the defense contention that her body showed signs of an assault or of trying to defend herself. He also said nothing in the evidence contradicts Pistorius' version of events.
When police entered the house, Steenkamp was dressed, wearing white shorts and a black vest.
Botha described two past police encounters involving Pistorius, suggesting he is prone to violence.
The first involved an incident at a Johannesburg restaurant in which a gun was discharged. Botha said Pistorius asked someone else to take the blame for it.
Police said the second incident took place at a racetrack where Pistorius threatened to assault someone.
The charge of premeditation makes it more difficult for Pistorius' attorneys to argue he should be released pending trial. To win bail, the defense must argue that "exceptional circumstances" exist that would justify Pistorius' release.
In a statement read by his lawyer Tuesday, Pistorius said he would not try to flee or influence any witnesses if he is allowed out on bail, and he said his release wouldn't be a danger to public order.
Magistrate Desmond Nair upgraded the charge against Pistorius to premeditated murder Tuesday, saying he could not rule out the possibility that the track star planned Steenkamp's death. But Nair said he would consider downgrading the charge later.
Pistorius' affidavit in alleged murder of girlfriend
A tragic mistake?
While prosecutors and defense lawyers agree Pistorius shot Steenkamp, the track star denied intentionally killing her.
"I fail to understand how I could be charged with murder, let alone premeditated murder because I had no intention to kill my girlfriend," Pistorius said in his statement.
"We were deeply in love and couldn't be happier," he said. "I loved her and I know she felt the same way."
In his statement, Pistorius said Steenkamp came to his home on February 13 for a quiet dinner. They wrapped up the night with a bit of television in bed for him, some yoga for her. She had brought him a Valentine's Day present to open the next day.
After the couple had gone to bed, he said, he got up in the early hours of February 14 to close the balcony door in his bedroom when he heard a sound in the bathroom.
Pistorius said he'd been a victim of violence and burglary in the past, and realized with terror that contractors who worked at the house had left ladders outside.
Fearing someone had entered the home through an open bathroom window, Pistorius grabbed his 9 mm pistol from under the bed, moved in the dark on the stumps of his amputated legs and yelled at what he thought was the intruder to get out.
"I fired shots at the toilet door and shouted to Reeva to phone the police. She did not respond and I moved backwards out of the bathroom, keeping my eye on the bathroom entrance," he said in his statement.
"Everything was pitch-dark in the bedroom and I was still too scared to switch on a light."
"When I reached the bed, I realized that Reeva was not in bed. That is when it dawned on me that it could have been Reeva who was in the toilet. I returned to the bathroom calling her name," he said.
He said he threw open the balcony door and screamed for help, put on his prosthetic legs and tried to kick in the door to the separate room inside the bathroom containing the toilet. Then, he said, he picked up a cricket bat, smashing panels out of the door before finding a key and unlocking it.
"Reeva was slumped over but alive," he said.
Pistorius said he called for help and was told to take her to the hospital himself.
He carried her downstairs and tried to help her, but she died.
A premeditated murder?
Prosecutors, however, painted a different picture.
They rejected Pistorius' claim that he mistook Steenkamp 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 her through a bathroom door after a heated argument.
Roux, the defense attorney, questioned the state's argument, asking how prosecutors would know Pistorius had put on his prosthetic legs and walked to the bathroom before shooting his girlfriend.
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.
Case rivets fans and friends alike
The case of the global sports hero known as the Blade Runner has riveted stunned fans around the world.
Social media reaction to the case appeared to come down against the sports star, but was still noticeably mixed on CNN's Facebook page.
"There's no amount of tears that will save you," said Anthonia Nneka Nwabueze. "Pistorius must face the law for brutally killing an innocent girl -- Reeva."
"My favorite athlete but what he did is grave and must be punished," Carlos Alvarez Ochoa said.
But another person who posted called for patience.
"(N)one of us were in the house when his girlfriend was murdered, let's hold off on casting stones at Oscar Pistorius," said Adrian van Liere Since. "Just like anyone else, he deserves a just trial, and in my eyes remains innocent until proven guilty."
Coming to his defense were two acquaintances.
"I've never seen him show an angry side. I've never seen him lose his temper," Vanessa Haywood, a model and longtime friend, told CNN. "He's an incredibly kind and gentle human being."
Another endorsement came from a former girlfriend.
"I would just like to say, I have dated Oscar on off for 5 YEARS," Jenna Edkins said on Twitter. "NOT ONCE has he EVER lifted a finger to me, made me fear for my life."
Robyn Curnow and Kim Norgaard reported from South Africa, and Ed Payne reported and wrote from Atlanta. CNN's Nkepile Mabuse also contributed to this report.