ROOSEVELT — Tooele County prosecutors will decide whether a Utah Highway Patrol trooper should face criminal charges for his decision to Taser a motorist during a 2007 traffic stop in Uintah County.

Paul Murphy, spokesman for the Utah Attorney General's Office, told the Deseret Morning News in an e-mail Wednesday that investigators have completed their independent probe into UHP Trooper Jon Gardner's decision to Taser Jared Massey during a Sept. 14 traffic stop. Murphy said the information gathered during the investigation has been turned over to Tooele County prosecutors.

"The Tooele County attorney will make the determination whether or not anything warrants criminal charges," Murphy said.

Gardner, a 14-year UHP veteran, stopped Massey on U.S. 40 west of Vernal on suspicion of speeding. Video of the traffic stop — captured by the camera in Gardner's patrol car and later obtained by Massey, who had it posted to the Internet site YouTube — showed the trooper ordering the 28-year-old out of his sport utility vehicle after he refused to sign a speeding ticket.

Massey has said he believed he was being allowed to show Gardner a nearby speed limit sign to prove he wasn't speeding. Instead, the trooper ordered Massey to turn around and put his hands behind his back. When Massey failed to follow that order, Gardner drew his Taser and leveled it at Massey's chest.

"What the heck's wrong with you?" Massey asked as he turned and started walking back toward his vehicle.

After issuing two more commands for Massey to put his hands behind his back, Gardner shot the telephone company engineer with his Taser, causing him to stiffen, scream and fall backward. Gardner fired the Taser a second time because Massey didn't comply with orders once on the ground, the UHP said.

Public outcry over the video, which was viewed more than 1 million times on YouTube, prompted the Utah Department of Public Safety to conduct a review of the stop. In November, UHP Col. Lance Davenport said an initial investigation showed that Gardner's use of the Taser was "lawful and reasonable under the circumstances."

"Officers are often forced to make split-second decisions or judgments in circumstances that are tense, uncertain or rapidly evolving," the colonel said during a Nov. 30 press conference, adding that Gardner did not know if Massey had a weapon.

During the press conference, Davenport said the attorney general's office had been asked to take an independent look at the incident. DPS Commissioner Scott Duncan added that the department also would conduct its own internal affairs investigation into Gardner's use of force and review its Taser-use policy.