PHOENIX -- Phoenix police arrested a murder suspect after receiving a tip from a witness.Police received a call Friday afternoon from someone who reported witnessing a homicide the night before.Officers were directed to a residence near Peoria and 15th avenues and found the body of Gregory Luecke, 28. Sgt. Tommy Thompson said the witness gave information that led to the identification of James Dover, 20, as the suspect.Detectives learned there was an altercation at the residence involving Luecke and Dover. "At some point, Dover shot and killed Luecke, who was unarmed, then fled the scene," Thompson said in a news release.Dover surrendered to officers at a motel near Interstate 17 and Indian School Road on Sunday. He was booked into the Maricopa County Jail on one count of second-degree murder.