PRETORIA, South Africa -- South African prosecutors pushed Friday to keep Oscar Pistorius behind bars, painting the double-amputee track star as a killer offering an improbable defense in the shooting death of his model girlfriend.
The picture offered by the prosecution came during the fourth day of a bail hearing that has been remarkable for not only its length but its allegations of miscues by a lead police investigator who himself faces attempted murder charges.
Prosecutors are trying to keep Pistorius jailed pending his trial on a charge of premeditated murder in the February 14 shooting death of Reeva Steenkamp, 29.
"He must realize that long-term imprisonment is almost guaranteed. He might think he'll be acquitted," Prosecutor Gerrie Nel told the judge in a packed Pretoria courtroom.
"We all know that a lot of important people were granted bail and they stayed in the country. But lots of very important people have escaped."
The prosecution has had several notable missteps during the bail hearing that began Tuesday, including admissions by the lead investigator that police could have contaminated the crime scene and failed to properly catalog evidence.
The South African Police Service pulled the investigator, Hilton Botha, from the case Thursday after prosecutors reinstated seven counts of attempted murder charges against him. Botha is accused of opening fire on a minibus full of people while allegedly drunk in 2011.
Prosecutors allege that Pistorius, 26, killed his girlfriend after a heated argument in the early morning hours of Valentine's Day.
The sprinter, however, says he thought an intruder was hiding in a toilet room inside the bathroom of his Pretoria home. He says he fired into the room in a fit of terror before realizing Steenkamp was inside.
Prosecutors say they are worried Pistorius will flee the country, if he's released.
But he has pledged to stay in South Africa and fight the charges, adding that he's unlikely to escape notice as a well-known athlete who walks on prosthetic legs.
Court officials learned Thursday that prosecutors had restored the charges against Botha. The charges had previously been withdrawn for additional investigation, but prosecutors decided a day earlier to proceed, said Commissioner Riah Phiyega of the South African Police Service.
Phiyega praised Botha, saying he is an experienced investigator who "has presented the case of the police well."
Botha was replaced by the department's most senior detective, Vinesh Moonoo. The move, Phiyega said, positioned the department for a "long-haul" investigation of the killing.
During the bail hearing, being held in a dark, stuffy Pretoria courtroom, defense attorney Barry Roux hammered away at the credibility of Botha and the entire police investigation.
He argued police had missed a bullet where Steenkamp was shot and may have contaminated the crime scene by failing to wear protective foot covers.
Botha said investigators didn't wear the booties because they'd run out.
Accusations against the investigator will be little more than a "speed bump" in the Pistorius case, said Bulelwa Makeke, the spokeswoman for South Africa's National Prosecuting Authority.
Positioning the prosecution
In arguments wrapping up during Thursday's session, the prosecutor said Pistorius' defense team has failed to explain why investigators found two cell phones and the gun believed to have been used in the shooting in front of the shower.
That goes to the prosecution claim that Steenkamp didn't merely get up to relieve herself in the middle of the night, but in fact had locked herself in the bathroom with her cell phone to protect herself from Pistorius.
Roux, meanwhile, got Botha to acknowledge during the hearing that investigators had failed to collect any evidence that counters Pistorius' argument that he mistakenly shot Steenkamp.
Roux told Magistrate Desmond Nair that the prosecution's case had suffered a monumental collapse.
The defense attorney also questioned police claims that a witness who lived at least 300 meters (328 yards) from Pistorius' home had heard a raging argument coming from the home.
He also said officers had failed to properly investigate and catalog evidence found there, including ammunition and a bottle of what Botha first called testosterone before backtracking.
Roux said the substance is an herbal remedy.
Authorities have argued that ballistic evidence shows Pistorius had to intentionally target the toilet to strike Steenkamp, and he was standing on his prosthetic legs when he shot through the bathroom door.
Pistorius said in his statement that when he shot through the door, he was feeling vulnerable to an intruder because he was not wearing
his legs and had limited mobility.
Pistorius made history last year as the first disabled athlete to compete in the able-bodied London Games. A few weeks after the Olympics, he smashed a record to win the men's 400-meter in the 2012 Paralympic Games.
When Pistorius was 11 months old, his legs were amputated below the knees because he was missing the fibulae.
He runs on special carbon fiber blades, earning the nickname "Blade Runner."
The case has roiled South Africa where Pistorius is considered a national hero.
Following his arrest on Valentine's Day, Pistorius put his career on hold and pulled out of future races. His sponsors, Nike and Oakley, suspended their contracts with the runner.
If Pistorius is released on bail, he will resume training next week, said his coach, Ampie Louw.
Robyn Curnow reported from Pretoria, and Chelsea J. Carter reported and wrote from Atlanta. CNN's Michael Pearson, Ben Brumfield, Kim Norgaard and Diane McCarthy contributed to this report.