The Serial Killer's Apprentice

The Serial Killer's Apprentice (2025) on 123movies: documentary and crime film starring Katherine Ramsland and Wayne Henley. Plot summary, full cast and release details. Dr. Katherine Ramsland interviews Elmer Wayne Henley, the sole survivor of the 1973 Houston Mass Murders, to unravel his chilling journey from manipulated teen to convicted killer — and the terrifying truth behind the line between victim and predator.