The Brief 18-year-old Jonathan Castelan was arrested and formally charged with murder in the fatal stabbing of 15-year-old Aziel Zacapala in El Monte. Castelan faces charges of murder, attempted murder, and assault with a deadly weapon following the July 10 attack. Law enforcement has not yet publicly released a motive for the attack or specific details regarding the other victims involved. An 18-year-old man faces murder and attempted murder charges in connection with a triple stabbing that tragically claimed the life of 15-year-old Rosemead High School football player Aziel Zacapala in El Monte. Investigators from the Los Angeles County Sheriff’s Department Homicide Bureau identified 18-year-old Jonathan Castelan of South El Monte as the suspect in the triple stabbing.