Danville Police Chief Daniel J. Weckessel, right, and an unidentified Danville Police officer look over the police station parking lot where officer Thomas Cottrell was gunned down Sunday night, Monday, Jan. 18, 2016 in Danville, Ohio. A man whose ex-girlfriend reported that he was armed and looking to kill police was in custody on Monday suspected in the death of Cottrell. (Doral Chenoweth III/Columbus Dispatch via AP)

COLUMBUS, Ohio - A man whose ex-girlfriend reported that he was armed and looking to kill police was in custody on Monday suspected in the death of an officer whose body was found behind the municipal building of a small Ohio town, authorities said.

The body of Danville Officer Thomas Cottrell was found late Sunday night, about 20 minutes after the ex-girlfriend of Herschel Ray Jones called dispatchers to report that officers in Danville were in danger, Knox County Sheriff David Shaffer said.

Shaffer said dispatchers tried to make contact with Cottrell after receiving the tip around 11:20 p.m., but couldn't reach him.

The sheriff's office then searched the village and found Cottrell's body, Shaffer said. His service weapon and cruiser were missing.

Officials did not immediately say how Cottrell died. But Chief Jim Gilbert, the chief deputy of the Franklin County Sheriff's office, tweeted early Monday: "Prayers for Ohio's first fallen officer for 2016 a Danville PD Officer was shot/killed this evening in Knox County."

Jones was taken into custody around 1:30 a.m. following a short foot chase after he was spotted running from a home in Danville, which is about 60 miles northeast of Columbus.

Knox County Prosecutor Chip McConville said he expects a murder charge will be filed against Jones, but he didn't know how soon that could happen. The Ohio Bureau of Criminal Investigation was still collecting evidence Monday, and Cottrell is scheduled for an autopsy Tuesday in nearby Licking County.

Jones was being held Monday for violating the conditions of his release from prison last year. McConville said that's enough to hold him until he is formally charged.

"There are a lot of things that have to happen before we make any charging decisions," McConville said.

Calls to numbers listed to Jones or family members in Knox County rang answered or were not in service Monday.

Jones, 32, has a lengthy criminal history and in one case tried to claim he was legally insane, according to court records. Knox County court records show Jones has multiple convictions for breaking and entering, burglary, receiving stolen property and carrying a concealed weapon dating back to 2001. In a 2011 case, he pleaded not guilty by reason of insanity before changing his plea to guilty.

Ohio prison records show Jones served nearly four years for the 2011 convictions on charges of receiving stolen property and possession of chemicals for manufacture of drugs. He was released last April.

The president of the Ohio Fraternal Order of Police called Cottrell's killing an assassination.

"We ask all Ohioans to pray for peace and healing for Officer Cottrell's family, friends and co-workers," Jay McDonald said in a written statement.

"His assassination is the latest reminder of how dangerous police work is and how the police are targeted for violence," McDonald said.

News from © The Associated Press, 2016