Jud Burkett, Associated Press
Wearing shakles, handcuffs and a bullet-proof vest, Scott Curley is lead into 6th District Court for an extradition hearing Thursday, Sep. 2, 2010 in Kanab, Utah. A mental health expert a mental health expert for the defense characterized Curley as a paranoid schizophrenic on Tuesday.

FLAGSTAFF, Ariz. — An Arizona man accused of killing a Utah sheriff's deputy is incompetent to stand trial but eventually could assist his lawyers in a defense with the right medical treatment, a mental health expert testified Tuesday.

Scott Curley has been charged with premeditated first-degree murder in the 2010 shooting death of Kane County, Utah, Deputy Brian Harris. The defense and the prosecution agree that Curley is mentally ill and has a rudimentary understanding of court proceedings. But they disagree on the second prong that determines whether he is competent to stand trial — can he rationally and sufficiently help his lawyers in the case?

Barry Morenz, a mental health expert for the defense, characterized Curley as a paranoid schizophrenic. Although he's highly intelligent, Morenz said Curley is guided by delusional beliefs and experiences auditory hallucinations that, with changes to medication, could recede to the background.

"His perception of reality is much different than yours or mine or everyone else's in the courtroom," Morenz said. "His perceptions of reality are very, very strange, they're bizarre. They're at the end of a bell curve."

Morenz did not come to the same conclusion, nor administer the same tests, as experts for the prosecution.

Prosecutors challenged Morenz's methodology and research, and said he provided no factual basis for his conclusion that Curley is incompetent. Curley has described the shooting consistently, saying he hid under a tree and intently fired his gun at someone who didn't listen to his demands to freeze, prosecutors said. He also has told family members that he understands a possible insanity defense and has a strategy to pursue it, prosecutors said.

Curley has pleaded not guilty in court to the murder charge, as well as charges of aggravated assault on a police officer and a citizen, and burglary and theft. In another sign of competency, prosecutors said Curley's answers to questions from two mental health experts over 14 months about whether he would take a plea deal were consistent.

Curley responded in one interview that he's more likely to take a plea agreement, although one hasn't been offered to him. His trial is scheduled for October.

"If they offer me a lesser penalty than life, it just makes sense for me to take it," Curley was quoted as saying by prosecutors. "I'm guilty. If I didn't take an offer, I'd be a fool."

Curley sat silent throughout the hearing, with family members seated behind him in the courtroom. Harris' family members and friends filled the rows on the opposite side.

Harris, 41, was tracking Curley, who was wanted for burglary when he was ambushed in August 2010, authorities said. Following the shooting, Curley fled on foot into the wilderness along the Arizona-Utah border. He was captured four days later near Kanab, Utah.