(CBS/AP/KPHO) PHOENIX - Police are investigating a possible link between a sheriff's deputy shot to death while answering a burglary call and a New Hampshire couple found dead in their car in Arizona. Authorities believe the victims were killed by the same gunman.
Deputy William Coleman, 50, was shot early Sunday at a Phoenix medical building when a man got out of a van and opened fire, striking Coleman under his bulletproof vest. Maricopa County Sheriff Joe Arpaio said the suspect was shot and killed by other deputies.
CBS affiliate KPHO reports Arpaio said Coleman was shot by a lone gunman who emerged from a minivan shooting when deputies arrived at the scene at a medical plaza.
"Our deputies approached the van and the suspect came out shooting with an automatic rifle," Arpaio said. "He killed our deputy. Two of our officers returned fire and killed the suspect."
According to the Boston Globe, a New Hampshire couple was found shot to death on Friday in their station wagon parked at a scenic overlook in Arizona.
Sheriff deputies found the bodies of James F. Johnson and Carol Raynsford, both 62, parked in a turnaround off a highway, according to a statement released by the Yavapai County Sheriff.
Deputies have not established a motive for the slaying of the New Hampshire couple, but their murder did not appear to have provoked, sheriff's spokesman Dwight D'Evelyn said.
"It doesn't appear it was provoked in any way, that's what makes it so unusual and baffling for our detectives," he said.
The Arizona Republic reported Coleman and the couple found dead off the highway were all shot with a high-powered rifle and the two crime scenes are connected by Interstate 17.
The theory the two shootings may be the work of the same gunman may explain why the man decided to open fire on the deputies, Deputy Jeffrey Sprong told the Republic.
"That connection is definitely something our investigators will look into," he said. "It wouldn't surprise me if it turned out to be the same guy."
Investigators are comparing evidence and expect to have the results sometime Monday.
Authorities have posted a reward and are asking anyone with information to call the sheriff's office or the county's Silent Witness program.