The finding indicates that the man cannot appreciate the charges against him, and cannot assist in defending himself in court. He was sent to the Utah State Hospital for treatment.
A review hearing was set for June 11.
Authorities allege 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.
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 a group of Polynesian males was trying to force their way inside.
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.
Officers returned fire and Opmanis was taken into custody.
Opmanis allegedly told police that when he realized it was, in fact, police officers at the door, he dropped his gun and surrendered.
Police said when they searched Opmanis' home they found 1.58 ounces of marijuana, a set of digital scales, two buy/owe sheets in a nightstand and a marijuana pipe.