Oscar Pistorius' murder trial has been told by South African state prosecutor Gerrie Nel to reject the Paralympic and Olympic track star's defence because it was "devoid of any truth".
Pistorius, who had his lower legs amputated as a baby, is accused of murdering his law graduate and model girlfriend Reeva Steenkamp at his home in Pretoria on Valentine's Day last year.
If convicted, he could face life in prison.
Since the trial opened in early March, Nel has portrayed Pistorius as a gun-obsessed hot-head who shot 29-year-oldSteenkamp four times through a locked toilet door where she was taking refuge after a heated argument.
The defence team says the track star was a vulnerable and caring boyfriend who killed Steenkamp in a tragic accident after mistaking her for an intruder hiding behind the door.
"We will argue that the accused's version should be rejected," Nel told the Pretoria court during his closing arguments.
"If the accused version is rejected it means my lady thatthere was no perceived intruder whatsoever."
Pistorius sat impassively through the opening minutes of the proceedings, which are expected to last two days. After that, judge Thokozile Masipa, who has more than 4,000 pages of evidence to review, will retire to consider her verdict.
Nel said a criminal trial was a "blunt instrument for digging up the truth" but that he was confident of his case.
He then said defense lawyers had argued that Pistorius acted in self-defense, fearing an intruder was in the house, but also raised the possibility that the once-celebrated athlete was not criminally responsible, accidentally shooting Steenkamp through a closed toilet door because he was "startled".
"It's two defenses that you can never reconcile," Nel said.
In addition to the murder charge, Pistorius faces three separate gun-related charges, one of which stems from his alleged firing of a shot in a crowded restaurant called Tashas in Johannesburg, months before he killed Steenkamp. He has pleaded not guilty to all charges.
Yesterday, some of the state's written arguments as well as transcripts of past testimony appeared on screens in the courtroom. One section questioned Pistorius' defense case:
"Is it putative self-defense? Is it an act of sane automatism? Did he have criminal capacity to act? Or was it all an accident as in Tashas Restaurant where he had the gun in his hand and it purportedly discharged itself?"
Because South Africa has no trial by jury, Judge Thokozile Masipa will decide with the help of two legal assistants if Pistorius committed murder, is guilty of a negligent killing, or if he made a tragic error and should be acquitted.
The runner faces 25 years to life in prison if convicted of premeditated murder, and also would be sent to prison for years if guilty of murder without premeditation or culpable homicide.
Earlier, Masipa told Nel and chief defense lawyer Barry Roux that they had only until the end of Friday to complete their final arguments in court.
"Unless, of course, you want to work on a Saturday and perhaps Sunday, after church," she said, smiling.