Police believe at least one killer was at large after eight members of one family were found slain Friday in the Midwestern state of Ohio.
The eight victims were found in four locations in Pike County in southern Ohio, Sherrif Charles Reader said at a press conference.
The victims, each shot execution-style in the head, included seven adults and one juvenile. Three children - a 4-day-old, a 6-month-old and a 3-year-old - were found alive, though it was not clear if they had sustained any injuries.
Reader said it was "strong" possibility that whomever was behind the acts was "armed and extremely dangerous."
Ohio Attorney General Mike Dewine said that authorities believed that one or more perpetrators "are still at large."
"This is a horrible, horrible tragedy," he said.
Ohio governor John Kasich, currently campaigning on the East Coast for the Republican presidential nomination, called the news "tragic beyond comprehension" in a tweet.
The FBI office in Ohio has offered assistance to local authorities, and the Ohio Bureau of Criminal Investigation has sent 12 investigators to the scene, a spokeswoman said.