A Danville woman called authorities around 11:20 p.m. ET and told them her ex-boyfriend, Herschel Ray Jones, had left with weapons and was looking to kill an officer, the statement said.
Dispatch personnel tried to make contact with the Danville officer but were unsuccessful.
Authorities from Knox County Sheriff's Office searched the village before finding Police Officer Thomas Cottrell on the ground behind the Danville Municipal Building. He was dead.
Officials saw Cottrell's service weapon and vehicle were missing, they said.
A man was observed running from a residence at about 1:36 a.m. ET, police said. After a short chase on foot, the suspect was identified as Herschel Jones III and was taken into custody, police added.
Officers from the Knox County Sheriff’s Office and the Ohio Bureau of Criminal Investigation are investigating the incident.