MESA, Ariz. - Mesa police are investigating a weekend homicide at a residence near Sossaman and Baseline roads.Just before midnight on Saturday, police detained five subjects for questioning after responding to a shooting at the home. Police determined that the suspect fled the scene. The five people were questioned and released.SWAT units entered the residence to check on the victim and found him deceased. He has been identified at Garret Duncan, 20.An assault rifle was found lying next to Duncan. Police searched the area for the suspect, but he was not located. On Sunday morning, Vinchenzo Luna Salas walked into a police station in Mesa and turned himself in.There is no word on what led up to the shooting or the charges Salas faces.