oscar pistorius
Oscar Pistorius will undergo a mental health evaluation that could last up to a month. Reuters

Oscar Pistorius will undergo psychiatric testing for up to 30 days starting on May 26 to determine whether mental illness played any role in the murder of girlfriend Reeva Steenkamp, according to media reports.

The South African Olympian’s murder trial will be postponed until June 30. Pistorius will be monitored as an outpatient from 9 a.m. to 4 p.m. at a psychiatric hospital. Judge Thokozile Masipa, who said on Tuesday she didn't want to "punish him twice," broke with precedent by not having Pistorius stay at the mental facility overnight, according to the New York Daily News.

Pistorius's defense team recently called upon psychiatrist Dr. Merryll Vorster, who testified that she believed Pistorius had a childhood anxiety disorder that may have contributed to him killing Steenkamp. Chief prosecutor Gerrie Nel followed by requesting that Pistorius be sent for independent psychiatric tests.

Mental illness could be a used as grounds for acquittal, or if convicted, a lighter sentence.

Kelly Phelps, a senior lecturer at the University of Cape Town's law department, told USA Today that the psychiatric evaluation panel could produce three outcomes: 1) that the anxiety disorder made Pistorius unable to distinguish right from wrong, which would find him not guilty due to mental illness; 2) Vorster's assessment is correct, and that Pistorius has an anxiety disorder which contributed to him believing he was acting in self defense against a possible intruder; 3) Pistorius doesn't have an anxiety disorder.

The Pistorius psychiatric evaluation means that the trial could be postponed for two months. The trial began on March 3 and is in the eighth week of proceedings.

Pistorius claims he shot Steenkamp through a toilet stall door on Feb. 14, 2013 by mistake, believing she was an intruder. If found guilty, Pistorius could face 25 years to life in prison on the premeditated murder charge.