PRETORIA, South Africa -- The chief prosecutor in the murder trial of Oscar Pistorius on Tuesday asked that the double-amputee runner be placed under psychiatric evaluation after an expert witness testified that he had an anxiety disorder.Prosecutor Gerrie Nel noted that a psychiatrist for the defense had testified that the disorder she diagnosed in Pistorius may have played a role in his fatal shooting of girlfriend Reeva Steenkamp in his home on Feb. 14, 2013. The prosecutor has acknowledged that an evaluation of Pistorius' state of mind at a government facility could mean the trial, which began March 3, will be delayed.Judge Thokozile Masipa ordered an adjournment and said she would rule on Nel's request on Wednesday morning.Nel questioned why the defense decided to ask Dr. Merryll Vorster, a psychiatrist, to testify on behalf of the Olympic runner. He has suggested that the trial is not going well for Pistorius and that his lawyers are floating the idea that a disorder contributed to Steenkamp's shooting and that therefore Pistorius bears less responsibility for her death.Pistorius says he mistook Steenkamp for an intruder when he shot her through the closed door of a toilet cubicle. Prosecutors say he killed her in anger after an argument.In asking for another professional evaluation of Pistorius' mental state, Nel appeared to be trying to ward off any attempt by the defense to say Pistorius should be treated favorably by the court because of a mental condition linked to his disability.Pistorius' chief lawyer, Barry Roux, said at the start of defense-led testimony that the double amputee's vulnerability and disability was at the center of his case of a mistaken killing. He said Pistorius should not be sent for 30 days of psychiatric evaluation and that he wanted to call another witness to continue testimony.The psychiatrist, Vorster, met Pistorius this month, prompting the prosecutor to question whether the timing of her late entry to the stable of defense witnesses signified a change in tactics by the defense, which has said Pistorius fired out of fear that he was about to be attacked.---Imray reported from Stellenbosch, South Africa.