Halls said on Friday that Yazzie's family provided his office with documentation from a physician detailing that since the accident, Yazzie has been confined to a wheelchair and has the mental capacity of a 10-year-old.
"It's an unfortunate circumstance," Halls said. "He received severe injuries in the accident."
On April 21, Yazzie left a Moab restaurant without paying, according to charges filed in 7th District Court, took a 2003 Ford Taurus and drove south on U.S. Highway 191. About 15 miles south of Moab, the Utah Highway Patrol has said, Yazzie crossed the center line and crashed head-on into Montoya's Ford Escape.
Montoya died at the scene. Yazzie received significant injury. A helicopter flew him to a hospital in Grand Junction, Colo.
Court documents claim Yazzie had a blood-alcohol level of 0.21 after the crash. Utah law considers .08 too drunk to drive.
The criminal charges were filed in July of last year. Halls said it took several months to verify Yazzie's diminished mental capacity and the extent of his injuries after the crash.