The Paralympic athlete has been on trial for the past six and a half months, while a Pretoria court sought to establish the truth behind the shooting of his girlfriend Reeva Steenkamp through a locked toilet door on the night of Valentine’s Day last year.
Pistorius and his legal team argue that he not guilty of murder, maintaining that he mistook Ms Steenkamp for a dangerous intruder and fired shots out of panic and fear. However, the prosecution says that he deliberately shot his girlfriend following an argument.
Even if athlete is acquitted of deliberately murdering Ms Steenkamp, he could still spend years in prison. The Blade Runner also faces three other unrelated charges – two for firing a gun in a public space, and one for illegally possessing ammunition.
Judge Masipa will scrutinise evidence given by 37 witnesses during the case. The verdict on whether Pistorius intentionally killed Ms Steenkamp is expected to take hours, but could run in to days.
How the biggest murder trial in the world unfolded
How the biggest murder trial in the world unfolded
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On Valentine's Day, Pistorius was arrested and charged with murder after shooting girlfriend Reeva Steenkamp in what he claims was a case of mistaken identity on 14 January, 2013
2/19 Oscar Pistorius
The couple had been dating for three months before the tragic shooting in the early hours of Valentine's Day
3/19 Oscar Pistorius
As the news of her death spread, world media descended on South Africa, where Pistorius enjoyed a national hero status after competing in the Olympics
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Scene of the tragedy: the house where Oscar Pistorius lived in Silver Woods gated community
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Pistorius was released on bail of one million rand (£73,000) after pleading not guilty of murder
6/19 Oscar Pistorius
In his bail application, Pistorius argued he shot his girlfriend thinking she was an intruder coming out to attack him. The state insisted the shooting was "premeditated"
7/19 Oscar Pistorius
Pistorius is facing three separated charges in connection with two gun-related incidents, including possession of illegal ammunition and two counts of discharging a firearm in public. He denies all charges
8/19 Oscar Pistorius
Described as the "trial of the century" in South Africa, the Oscar Pistorius case has dominated world headlines
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Pistorius arrives to the North Gauteng High Court in Pretoria ahead of his murder trial
10/19 Oscar Pistorius
An overcome Oscar Pistorius vomited in court as he listened to harrowing expert testimony about the autopsy of his girlfriend Reeva Steenkamp, whom he is accused of murdering
11/19 Oscar Pistorius
His court appearances have been dramatic with the athlete often breaking down in tears and vomiting
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If found guilty of premeditated murder, Pistorius could spend the next 25 years in prison
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Pistorius pictured arriving at the Weskoppies Psychiatric Hospital where he was ordered to undergo a 30-day psychiatric evaluation after an expert witness claimed he suffered from a generalised anxiety disorder. This was dismissed by a panel of independent experts.
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Members of a Facebook supporters' group of Oscar Pistorius wait for him to arrive at court
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Prosecutor Gerrie Nel has portrayed Pistorius as a reckless, young man with an inflated ego and a short temper
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Defence counsel Barry Roux and his now famous "I put it to you" phrase have become an internet sensation
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The fate of Oscar Pistorius now rests in the hands of judge Thokozile Masipa
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Judge Thokozile Masipa ruled out premeditated murder charge
POOLKIM LUDBROOK/AFP/Getty Images
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Oscar Pistorius guilty of culpable homicide - and now faces up to 15 years in prison
Siphiwe Sibeko/AFP/Getty Images
The possible verdicts include:
Guilty of murder
If Pistorius is convicted of intentionally killing Ms Steenkamp, Judge Masipa will have to decide whether the murder was premeditated or not. In South Africa, premeditated murder carries a life sentence in prison with a minimum of 25 years before the chance of parole.
Pistorius could also be convicted of murder without pre-planning, which carries a minimum sentence of 15 years in prison.
Guilty of culpable homicide (manslaughter)
If Judge Masipa finds that Pistorius did not intend to kill Ms Steenkamp, but did so by firing recklessly, he would be acquitted of murder, but may face a charge of culpable homicide (manslaughter). This focuses on negligence rather than intent, and so carries a lesser sentence of five years, which can be increased or decreased depending on the circumstances surrounding the killing.
Guilty of discharging firearms in public
Pistorius is also charged with two unrelated charges of discharging a firearm in public – once in restaurant in 2013, and once through a car sun roof in 2012. The athlete could be sentenced to five years in prison on each count, however Judge Masipa would be far more likely to impose a non custodial sentence such as a fine.
Guilty of illegal possession of ammunition
Pistorius has admitted to being in possession of ammunition for an unlicensed firearm. This could carry a sentence of 15 years in prison.
Not guilty on all charges
If Judge Masipa accepts that Pistorius had no intention to kill and acted in self-defence - formally known as ‘putative private defence’ - and was not guilty of the other three charges that have been brought against him, he would leave the court a free man.
Sentencing and appeal
If there is a conviction, a second trial will begin with the prosecutors and defence will have the chance to present further witnesses – from family members to psychiatrists – before Judge Masipa decides if and how long Pistorius goes to prison.
After a sentence is delivered, Pistorius will be able to appeal both the conviction and the sentence.
Additional reporting by AP