The defence in the murder trial of Oscar Pistorius is due to begin setting out its case, with the athlete himself expected to take the stand.
The trial, in the South African city of Pretoria, has already heard 15 days of prosecution-led testimony.
Mr Pistorius denies deliberately shooting his girlfriend, Reeva Steenkamp, in February 2013, saying he mistook her for an intruder.
Prosecutors allege that he killed her after an argument.
The BBC’s Karen Allen in Pretoria says that although Mr Pistorius is not legally obliged to testify he is the only witness to the alleged murder.
His lawyers have previously told journalists that it was “likely” they would call him to give evidence first, she adds.
Prosecution testimony has relied on accounts from neighbours and specialist ballistics, forensic and mobile phone evidence.
Our correspondent says the defence will have to address key questions, in particular:
- Allegations from witnesses that Oscar Pistorius was reckless with guns and had fired a pistol indiscriminately on two occasions in the past
- Why he didn’t check the whereabouts of Ms Steenkamp when he feared an intruder was in the house
- Why, as a person used to handling weapons, he didn’t fire a warning shot