South African athlete Oscar Pistorius has pleaded not guilty at the start of his trial for the murder of his girlfriend Reeva Steenkamp. Mr Pistorius shot Ms Steenkamp, 29, a model and reality TV star, at his home in Pretoria on 14 February 2013.
State prosecutors allege the killing was premeditated, but he claims he mistook her for an intruder.
For the first time in South Africa, parts of the trial will be televised live. Media interest is high.
The arrest of the national sporting hero astounded South Africa.
The 27-year-old double amputee won gold at the London 2012 Paralympic Games and also competed at the Olympics.
Mr Pistorius pleaded not guilty to all charges, including the “wilful and intentional murder of Reeva Steenkamp” as the trial began.
His lawyer read out a statement from the athlete, giving his version of events of how Ms Steenkamp died, saying he believed his girlfriend was in bed when he shot at the toilet door in the early hours of Valentine’s Day last year.
The start to proceedings at the court in the capital were delayed by 90 minutes as a Afrikaans translator was absent.
The BBC’s Andrew Harding in the courtroom says Mr Pistorius looked calm, or at least neutral as he arrived in court – a far cry from the emotional wreck he seemed at the bail hearing last year.
Mr Pistorius’s uncle, brother and sister are also in court; next to them on the relatives’ bench is the family of Ms Steenkamp, including her mother June, our correspondent says.
Gerrie Nel, who is leading the prosecution team, read out the indictment and has called the first witness, Michelle Burger, a neighbour of Mr Pistorius who has requested that her testimony not be televised.
She says she awoke hearing a woman’s screams and heard a call for help.
The BBC correspondent says Mr Nel, who has begun to lay out the state’s case, is a quiet, determined figure – “fox-like”, according to a friend and fellow-lawyer.
State prosecutors say Mr Pistorius planned the killing and shot Ms Steenkamp after a row.
But Mr Pistorius says he shot his girlfriend through the bathroom door of his home in Pretoria after mistaking her for a burglar.
If found guilty of premeditated murder, he could face life imprisonment.
He has also been charged with illegally possessing ammunition.
There are no juries at trials in South Africa, and his fate will ultimately be decided by Judge Thokozile Matilda Masipa.
Much of the case will depend on ballistic evidence from the scene of the shooting, correspondents say.
On the anniversary of the shooting, Mr Pistorius released a rare statement in which he said: “The loss of Reeva and the complete trauma of that day, I will carry with me for the rest of my life.”
Last week, a judge ruled that an audio feed of the whole trial could be broadcast. Some parts will also be televised, including opening arguments, evidence of experts, police witnesses and closing arguments.
The testimony of the accused and his witnesses is exempt.
One South African TV station, MultiChoice, has set up a dedicated Oscar Pistorius Trial channel to provide 24-hour coverage. It is due to begin broadcasting on Sunday.
Defence lawyers had said it would prejudice proceedings.