A 35-year-old Fairbanks man exited a pickup with his clothes on fire after Alaska State Troopers fired a chemical agent inside the truck.

Troopers say Jeffery M. Whaley, a convicted felon, was treated for injuries. Troopers have recommended that state prosecutors charge the man with weapons misconduct and driving under the influence of alcohol or drugs.

Troopers said they encountered Whaley while responding to a call Wednesday about someone slumped over their steering wheel outside a convenience store between Fairbanks and North Pole.

A witness said the man had a gun in his hand and a bottle of beer next to him. Troopers said Whaley is a convicted felon who is not allowed to possess a gun.

Troopers approached and attempted to get him to leave the truck. When he refused, troopers with assistance from Fairbanks police used armored rescue vehicles to pin the pickup in place.

Officers attempted to force Whaley from the truck with non-lethal munitions. In their final attempt, they used a "stinger grenade," troopers spokeswoman Megan Peters said in an email response to questions.

The device contains rubber pellets and a small amount of oleoresin capsicum, which is used in pepper spray. The device was deployed according to the manufacturer's guidelines, troopers said.

The stinger grenade landed in the suspect's lap, Trooper Lt. Brian Wasserman told Fairbanks television station KTVF.

It discharged when he sat on it, troopers said.

"There is some heat that's generated from those, but they're designed for indoor use," Wasserman said.