A Bar Nunn man pleaded guilty Monday to one count of driving under the influence that caused serious bodily injury by killing another man in December.

Tracy Matekovic, 33 at the time of his arrest, entered his plea before District Court Judge Thomas Sullins.

Family members of the man, Chris Sanders, killed in the head-on collision Dec. 9, sat quietly, with some crying, as Matekovic entered his plea.

In exchange for the plea, the state agreed to drop three other charges, Assistant District Attorney Dan Itzen said. Those charges were interference with a police officer, breach of peace and battery.

The DUI serious bodily injury count carries up to a penalty of 10 years behind bars and a fine of between $2,000 and $5,000, plus other court costs and fees.

He has three prior DUI’s on his record.

Itzen and Matekovic's public defender Rob Oldham have agreed on a prison sentence of five-and-a-half years. A pre-sentence investigation will be completed before his sentencing, Sullins said.

According to law enforcement, in December, officials were called to the intersection of Highway 20/26 and North Six Mile Road west of Casper, for a two-vehicle head on collision.

Investigators said Matekovic was driving in the wrong lane of travel when he collided head-on with another vehicle driven by 38-year old Sanders, who was pronounced dead at the scene.

A Wyoming Highway Patrol trooper said that Matekovic had a strong odor of alcohol coming from him.

While at the Wyoming Medical Center for treatment, police and hospital personnel said he caused a disturbance and was combative.

Monday, Matekovic told Sullins he didn't know how much he had to drink on the night of the collision.

He remains free on $15,000 bond.