Complex sentence: One month later, on July 14, Bishop killed his final victim: 13-year-old Graeme Cunningham, who vanished from his neighbourhood prior to embarking upon a camping trip with a friend and an adult chaperone: one Arthur Bishop.
Split into simpler sentences: One month later, on July 14, Bishop killed his final victim: thirteen-year-old Graeme Cunningham. Cunningham vanished from his neighbourhood prior to embarking upon a camping trip with a friend and an adult chaperone: one Arthur Bishop.