NEW YORK (AP) — A psychiatric patient’s ability to stand trial in a deadly meat-cleaver attack at a therapy office abruptly came under question Friday as jurors were being chosen.

After David Tarloff refused to leave a courthouse holding cell and his lawyer said Tarloff wouldn’t respond to questions, a judge ordered a psychiatric examination that could indefinitely delay the trial. The exam, set for Monday morning, will determine whether Tarloff is competent to proceed.

The episode marked the latest injection of uncertainty into a case long beset by questions about whether Tarloff would ever be tried. He faces murder and other charges in the February 2008 attack that killed psychologist Kathryn Faughey and seriously hurt her office mate, psychiatrist Dr. Kent Shinbach.

Tarloff, a schizophrenic, sometimes believes he’s the Messiah and God and the devil speak to him, his lawyer and doctors have said. He was found mentally unfit for about a year after his arrest.

Doctors said last year that his condition had improved enough for him to be tried.

He is planning an insanity defense, which isn’t related to whether he’s competent for trial. An insanity defense hinges on whether a person was so mentally ill when committing a crime that he or she didn’t understand it was wrong. Fitness for trial, on the other hand, concerns whether a defendant understands court proceedings and can assist in his or her defense.

Tarloff, 42, had exhibited some odd behavior — such as blowing kisses and grabbing at the air — at points during jury selection, which began Tuesday, said his lawyer, Bryan Konoski.

Tarloff was in court Friday morning. But he refused to return after a lunch break, court officers said. Konoski then found him unwilling to speak, except for some unintelligible whispers; Tarloff eventually turned his back and leaned his head against a wall of the holding cell, the lawyer said.

Konoski said he thought the stress of the impending trial had worsened Tarloff’s condition.

“I think it’s causing him to crack,” he said Friday evening. “He’s just a mess right now.”

But a prosecutor suggested Tarloff might be malingering.

The court has tried to accommodate Tarloff’s problems, such as by not handcuffing him as often as some defendants are, and he’s “taking advantage of that tone,” Manhattan assistant district attorney Evan Krutoy told a judge.

Faughey was slashed to death in her Manhattan office. Tarloff told police he’d aimed to rob Shinbach — who’d treated him 17 years earlier — to get money to get his mother out of a nursing home and take her to Hawaii.

Faughey confronted Tarloff, who told police he feared she would kill him.

Shinbach was seriously hurt trying to save her.

(Copyright 2010 by The Associated Press. All Rights Reserved.)