Oscar's toughest race

As Oscar Pistorius stood in the dock, his brother quoted a biblical reference that was particularly pertinent for the Paralympic champion.

"Let us run with perseverance the race marked out for us," wrote Carl Pistorius on Twitter, citing Hebrews 12:1 and adding the hashtag "#runyourrace".

Today the medal-winning runner faces what could be the toughest challenge of his life as he prepares to testify for the first time about the night he shot his girlfriend, Reeva Steenkamp.

His testimony, in the Pretoria High Court, will be given after a week's delay in the trial.

The delay was brought about by the illness of one of Judge Thokozile Masipa's assessors.

The unexpected break was hard for Pistorius, relations said, because he was "all geared up" to answer his accusers.

But it has given his defence team time to reflect on what the athlete will say about the events of StValentine's Day last year, when he fired four times through a locked toilet door at his Pretoria home, killing his girlfriend.

He has already made two statements - at his bail hearing last February and at the start of the trial in March - explaining that he believed that it was an intruder in the toilet cubicle.

The prosecution says he murdered Steenkamp after an argument.

Pistorius will be tested not just against his two previous versions of events, but also against the abundance of direct and circumstantial evidence supplied by witnesses called by the prosecution.

"In this case, the criminal conduct, the act itself, is freely admitted," said Stephen Tuson, a criminal lawyer and professor of law at Wits University, Johannesburg.

"The only issue for the court [to consider] is his state of mind, and the most direct evidence of that is his own testimony.

"If a criminal suspect is lying through his teeth, the court can dismiss his version as untrue if it finds his state of mind, as suggested by the circumstantial evidence, contradicts him."