SLIPPERY ROCK — Four state troopers testified at a preliminary hearing Wednesday about an incident earlier this month that ended with one of them on the receiving end of a headbutt.

Accused of throwing the headbutt while resisting arrest for DUI, Kristoffer M. Ion, 30, of Butler, appeared before District Judge Joseph Nash. He was brought from Butler County Prison, where he is being held in lieu of $100,000 bond.

On Wednesday, Nash moved forward all but one of Ion’s charges to Butler County Common Pleas Court, including one new felony charge, one felony count of fleeing and misdemeanor counts of DUI, simple assault and false identification to police.

Assistant District Attorney David Beichner added a felony aggravated assault charge to an enumerated person, which is specific to injuries caused to police officers, first responders and hospital staff, among others.

Trooper Matthew Stimac told the court about the alleged headbutt, which he said caused the fading bruise beneath his right eye. He said he and two other troopers were called April 3 to assist two troopers already at the scene, who were struggling to arrest Ion.

Stimac said as troopers worked to push Ion into the back seat of the cruiser, he entered through the front seat and straddled the center console to assist. He noted the cruiser was not equipped with a cage.

He said the headbutt came as things were supposed be winding down, after all four doors had been shut. He said he was attempting to let go of Ion and exit the vehicle.

“As soon as I removed my hands, he headbutted me,” Stimac said. “He forcefully drove his head into my face.”

Stimac said his eye swelled immediately and eventually bruised. He said he was released from a hospital the same night and did not miss work because of the injury.

Two troopers testified Wednesday with more emphasis on the DUI that drew police attention to Ion in the first place.

Trooper Zachary Swartz, of the Kittanning barracks, said he was off duty when he saw a white truck exiting its lane multiple times. He said he called the Butler barracks to report the erratic driver and he continued following in case the driver caused a crash.

“I wanted to maintain visual contact,” he said.

Responding to the report was Trooper Clinton Deemer, who said after spotting the vehicle in the opposite direction, he turned around and followed the truck. He said during that time, he saw Ion’s truck cross the fog line by “several feet.”

Deemer said when he activated his lights and siren, the truck continued down a driveway for about 100 yards. The driveway led to a Lancaster Township home. He said Ion misidentified himself and then failed field sobriety tests.

“As soon as I said, ‘Put your hands behind your back,’ he fled on foot,” Deemer said.

Deemer said he tackled Ion to the ground about 20 feet away, and he and his partner struggled but eventually handcuffed Ion and took him to the cruiser. Deemer said Ion kicked the cruiser’s front bumper and continued to stiffen his legs and body and generally resist.

“We were opening the door, and he kept kicking the door closed multiple times to prevent us from placing him inside,” Deemer said.

According to multiple troopers, after assisting troopers arrived, Ion’s legs were placed in a nylon restraint. Stimac said even with the restraint, Ion resisted.

“He laid out and would not put his head (or legs) in the vehicle,” Stimac said.

While Nash decided Wednesday’s testimony mostly aligned with the prosecutor’s case, he dismissed one misdemeanor count of DUI while driving on a DUI suspended license.

Ion’s attorney, Ken Harris, argued for its dismissal, as well as the dismissal of one felony count of aggravated assault. Though the latter remains, Harris pointed out the misdemeanor carries specifications related to blood-alcohol content.

“Technically you have to be over .12%,” Harris said.

During his testimony, state police Cpl. Michael Schmidt said Ion never was taken for a blood or breath test. He said he made the call based on Ion’s behavior and with fear that Ion would continue fighting troopers or possibly fight staff at the hospital.

“Personally, I have never made that decision until this night,” Schmidt said.

Schmidt also said after Ion was settled into the cruiser, his true identity was discovered, as well as a bench warrant for his arrest. Ion failed to appear for sentencing a 2018 case, involving a felony escape charge.

During discussion about bond, of which no changes were made, Harris informed Nash that Ion intended to enter a plea agreement for the earlier escape case.

Outside of those two cases, Ion has nine other pending cases in county court, involving an array of felony and misdemeanor charges.

For Wednesday’s case, Ion will next appear for formal arraignment in county court.