A 38-year-old man has been booked on two counts of first-degree murder in connection with the deaths of his parents, Phoenix police said.

Detectives are investigating a homicide that occurred early Monday morning and left Sam Miller, 73, and Marjorie Miller, 72, dead.

Their son, Jim Miller, is accused of shooting then at a home near 35^th Street and Campo Bello Drive, police said in a release.

Officers responded to a domestic violence call about 5:15 a.m. Feb. 12. The caller said that his father had shot and killed his mother, then turned the gun on himself, police said.

When they arrived, officers identified Jim Miller as the caller and detained him. Inside the home, they found his parents’ bodies. A roommate inside the home was unharmed, police said.

Investigators processed the scene, reviewed the evidence, spoke to witnesses and then interviewed Miller “where he admitted to shooting his parents sometime during the night,” the release stated.

The investigation remains active, police said.