Tempe police on Tuesday identified the two men who died in a suspected murder-suicide.

Edmund Keller, 32, and Landis A. Casner, 24, both of Tempe, died after shots rang out about 9:15 a.m. Monday in a neighborhood near Southern Avenue and McClintock Drive , said Sgt. Jeff Glover, a spokesman for the Tempe Police Department.

Police have reasons to believe that the shooting was planned, Glover said.

Glover said police suspect Casner waited outside Keller’s home and shot Keller when he answered the door. Police believe Casner then shot himself, Glover said.

Glover said police are investigating a potential motive that Casner might have had an infatuation with Keller’s ex-girlfriend, who is not in Arizona, Glover said.

Casner died outside of the residence, and Keller was transported to a nearby hospital, where he died from his injuries, Glover said.

No other details were available.