The hearing in Pretoria adjourned until Friday.
Pistorius, a double amputee, is accused of killing his girlfriend, 29-year-old model Reeva Steenkamp Feb. 14 by firing four shots through a bathroom door. Steenkamp was struck three times.
Pistorius said he was firing at what he thought was an intruder, not his girlfriend who was spending the night at his home in Pretoria.
He has been charged with premeditated murder.
In his closing argument Thursday, prosecutor Gerrie Nel said Pistorius' "total lack of insight and willingness to take responsibility for his deeds increases his flight risk," Britain's The Guardian reported in a live blog of the proceedings.
He noted the athlete kept his passport open and had off-shore bank accounts. Pistorius also has a home in Italy.
Nel said defense attorney Berry Roux failed to provide examples of exceptional circumstances that would warrant bail being allowed. Roux said his client gave his full version in an affidavit that makes sense and there wasn't anything to refute it.
"The question is why should he be further incarcerated in the interests of justice?" Roux said.
Citing two other confrontations involving Pistorius, Nel said the sprinter was "prone to violence. What else is threats and murder?"
By his own admission, Pistorius fired four shots, not one, Nel said.
"The only reason you fire four shots is to kill," the prosecutor said. "On his own version, he's bound to be convicted."
Pistorius won two gold medals and a silver at the 2012 Paralympic Games. Earlier last summer in London he became the first paralympic sprinter to participate in the Summer Olympics.
Magistrate Desmond Nair, who will decide whether Pistorius is granted bail, suspended the hearing during Roux's summation, saying there was a "threat of some kind" reported outside the courtroom.
Court security officials told media representatives they "know nothing" of threat and that Nair was acting on a warning from a bodyguard.
Meanwhile, the prosecution suffered a blow when it was revealed that the lead police officer in the case faces attempted murder charges.
South African police Detective Hilton Botha, who offered sometimes confused testimony Wednesday during the second day of the bail hearing, faces seven counts of attempted murder after allegedly opening fire on seven passengers in a minibus while drunk with two other officers, Pretoria Police spokesman Brig. Neville Malila said Thursday.
Malila said Botha and the other officers fired the shots in 2009 while trying to stop the vehicle, The Times of South Africa said. He was initially charged in the case but the charges were provisionally withdrawn and the case was referred to the independent director of public prosecutions.
"It was only yesterday [Wednesday] that we were informed by the DPP that [Botha] is being charged," Malila said.
Botha, scheduled to appear in court in May on the charges, will remain on the Pistorius case, Britain's Sky News reported.