The victim was Diego Castillo of San Diego, according to the county Medical Examiner's Office. He died at 11:37 p.m. in the 1000 block of Decker Street near where he was stabbed at 1050 E. Lexington Ave. a half-hour earlier.El Cajon police responded at about 11 p.m. to a 911 call about a fight between a group of men in the parking lot near Courtyard Villas Apartments and found Castillo with life-threatening injuries from a single stab wound.Officers began emergency life-saving measures until paramedics arrived. They were unable to revive Castillo, who was pronounced dead at the scene.Police took a suspect, 39-year-old Able Torres, into custody.El Cajon Police Department Sgt. W. Miller said homicide detectives were able to locate the knife used in the stabbing.Torres was booked into San Diego Central Jail. He is being held without bail on suspicion of first-degree murder.