Four people were found shot to death in rural Maine on Tuesday, and three motorists were wounded by gunfire on a nearby stretch of highway in a series of related incidents for which a single suspect has been arrested, state police said.
A man initially detained by police as a "person of interest" in all the shootings was later formally arrested and charged with four counts of murder, according to state police spokesperson Shannon Moss.
The man, considered a suspect in the highway gunfire as well but not charged with those shootings, was identified as Joseph Eaton, 34, of Bowdoin, a small town about 25 miles south of Maine's capital, Augusta.
Police said he was expected to make his first court appearance later in the week.
The investigation began late Tuesday morning when four bodies were discovered inside a Bowdoin home, followed by reports a short time later of several cars being fired upon along Interstate-295 in Yarmouth, about 25 miles (40 km) to the south, police said.
A search of a wooded area near the highway led to the suspect's arrest, and authorities said the four slaying in Bowdoin and the highway shootings were connected, although they declined to say how they were linked.
"It's still a very active investigation with a lot of moving parts," Moss told Reuters in an email.
A stretch of I-295 near Yarmouth, about 12 miles north of Maine's largest city, Portland, was shut down for at least an hour by the shootings and ensuing manhunt there.
Police provided no details about the circumstances of the gun violence, a possible motive for the shooting spree or identities of the victims. Moss said a news conference was planned for Wednesday afternoon.
Local media reported that one of the wounded motorists was hospitalized in critical condition and one in serious condition. Police said at least one of the victims had undergone surgery.