Opmanis had previously been ruled incompetent to proceed to trial. His mother, Deborah Preste, told the Salt Lake Tribune on Monday that her son was assaulted when he was 16 years old, and suffered brain damage. He now has the mental capacity of a 10-year-old, she said.
Tuesday's hearing was scheduled for a judge to hear testimony from doctors who have treated Opmanis at the Utah State Hospital, where he has been residing since he was ruled incompetent in March.
However, after about an hour of testimony, Judge Steven Hansen halted proceedings and set another court date for Dec. 10 so further neurological exams can be completed and other documentation provided to the court.
Utah County Sheriff's authorities allege that on Nov. 19, they announced their presence and used a ram to attempt to open the locked front door of Opmanis' home, according to a probable cause statement. The ram made a hole, but failed to open the door because it was locked.
When the door didn't open, a second officer started to kick and push the door while continuing to announce the officers' presence, according to court documents.
Opmanis allegedly fired a gun several times through the front door while the officer was kicking it. Police said he admitted to firing four rounds from a .22-caliber revolver at the front door because he thought it was a group of Polynesian males trying to force their way inside.
Officers returned fire, and eventually made their way through a back door of Opmanis' home. Opmanis told police that when he realized it was officers at his door, he dropped his gun and surrendered.
No officers were hit, but police say several were struck by either BBs from the shots fired or debris from the door and suffered injuries to their arms and faces.
Preste said her son had loaded the gun with "snake shots," intended to spray BBs, but not fatally injure a person. She said he was fearful because he had been threatened by members of a Polynesian gang who were upset with an acquaintance of Opmanis.
Preste said she hopes her son is ruled incompetent without the ability to be restored. She said her son is not mentally ill, but has physical brain damage, and should not be held at the state hospital.