Several of the victims, which included seven adults and a 16-year-old male, were killed in their bed in homes only a few miles apart.
Officers are searching for the killer or killers, who are probably armed and a danger to surviving family members, Pike County Sheriff Charles Reader said.
“We have a specific family that’s been targeted but I don’t think there’s been a threat to any other members of the community,” he said. “I’ve given the family precautionary measures to make. They know we’re available.”
At least three young children survived. One was 4 days old, one was 6 months old, and the third was 3 years old, Pike County Sheriff Charles Reader said. The youngest baby was found in bed next to the child’s dead mother.
State criminal investigators were interviewing a “person of interest” detained in Chillicothe, Ohio, early Friday night in connection with the deaths. No further information was given, but a vehicle was stopped at about 6:30 p.m. ET and officers from both the Chillicothe Police Department and Ross Count, Ohio, Sheriff’s Office detained what appeared to be two people at the scene.