Investigators are looking into whether mental illness played a role in the death of an off-duty eastern Pennsylvania deputy sheriff after he took his best friend -- another off-duty officer -- hostage at gunpoint before fatally shooting himself, police said.

State Police Cpl. Shawn Noonan said that investigators are trying to figure out what motivated Carbon County Deputy Sheriff David Midas and said they were interviewing co-workers and family members to see whether there were signs of mental illness.

"They're still trying to figure out the details," Noonan said.

People who knew Midas well say they just don't understand. Carbon County Commissioner Tom Gerhard described he and Midas as close friends who talked nearly every day.

"He was well known and well-respected by his co-workers and everybody he came into contact with. I'm devastated," Gerhard told the Republican Herald.

The Times News of Lehighton and WFMZ-TV identified the second officer as Christopher Ondrus, 34.

Noonan said the two officers were friends, and that Midas' death was not considered suspicious. Noonan had no information about Ondrus' condition, but that as far as he knew, he hadn't been injured.

Lansford Mayor Ron Hood told the Times News of Lehighton that Midas and Ondrus were best friends.

“He was easygoing, very outgoing. He got along with everybody. He was just a great guy -- everybody loved him.

“I remember flipping through channels and come up on a polka show, and there he was, dancing with all these little old ladies,” Hood said. “And on the radio, there would be all these polkas going out to ‘Officer Dave in Weatherly’.”

On Friday night, police say Midas, 33, of Weatherly, went to the police station in the small town of Lansford, where he was a part-time officer, and took ammunition and an unmarked police car before he drove to the home of another off-duty officer and took him hostage.

Midas then drove Ondrus to nearby Jim Thorpe, where a struggle began in the tourist town of Jim Thorpe, about 70 miles north of Philadelphia. Midas shot himself in the head, police say. He died early Saturday at a hospital, according to Lehigh County Coroner Scott Grim, who ruled Midas' death a suicide.

During the struggle, Ondrus tried to take the gun away from Midas, according to Carbon County sheriff, Dwight Nothstein.

Gerhard said counseling sessions were set up for fellow officers. He said Midas had been talking about a run for sheriff of Carbon County in 2015.

"I just gave him a list of events he should attend if he was going to run for sheriff," Gerhard said. "I gave him some advice my father gave another candidate some years ago about wearing your wedding band. His wife said she'd been trying to get him to wear it for years, but it took a commissioner to get him to wear it."

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