Pistorius returns to court

Paralympian Oscar Pistorius is back in court on Monday in Pretoria for the resumption of his murder trial following a month of psychiatric tests.

The South African sprinter's defence has argued that a "generalised anxiety disorder" contributed to him shooting dead his model girlfriend Reeva Steenkamp on Valentine's Day last year.

His case was put on hold and he begun a period of mental evaluation as ordered by Judge Thokozile at Masipa Weskoppies Psychiatric Hospital in Pretoria.

Pistorius admits shooting Steenkamp with a 9mm pistol through a locked toilet door, but says it was a mistake as he thought she was an intruder coming to attack him in the night.

The prosecution argues it was cold-blooded murder following a row between the young couple and has gathered evidence of a tempestuous relationship.

The judge's ruling followed testimony from an expert witness for the defence who claimed Pistorius suffers from an anxiety disorder that could explain why he reacted so violently to a perceived break-in.

His defence team has claimed the deep-seated anxiety dates back to the amputation of his lower legs as a child and the influence of a mother who abused alcohol and slept with a gun under her pillow out of fear of South Africa's high crime rates.

The outcome of Pistorius's assessment may be crucial in determining the direction of the trial, with leaked media reports suggesting the three specialists who monitored him had come to an "unanimous" conclusion about his state of mind.

If they diagnose a serious mental illness, Pistorius may get "admitted to psychiatric hospital indefinitely," said Sean Kaliski, a forensic psychiatrist who conducts hundreds of medical assessments annually at Valkenberg Hospital, a facility outside Cape Town.

But it is highly unlikely that a relatively minor disorder such as a generalised anxiety could have an impact on sentencing in a murder trial, Kaliski added.

"Never, never, no one has ever used it in a forensic sentence. It would be a first if this is used successfully now, a world first," he said. "It's usually serious matters - schizophrenia, dementia, bipolar disorder."

His trial started in March and has attracted global media attention. He has pleaded not guilty to Steenkamp's murder and other charges related to ammunition possession. He faces a maximum of 25 years in prison if convicted of murder.

Once all the evidence has been presented - estimated to take between one and two weeks - the defence and prosecution will require several more weeks to compile their written submissions before presenting them to court.

They will then return to court to answer final questions on their arguments. South Africa does not have jury trials, so a verdict will be delivered by the judge after a few weeks' deliberation.