Mike taught his cousin “the stealth maneuvers that one uses to take a life, showing him violent images, telling him dark stories,” Brucato said on Richard Ramirez: The Night Stalker Tapes.

Ramirez himself remarked on the phenomenon during an interview with biographer Philip Carlo, who would go on to write The Night Stalker: The Disturbing Life and Chilling Crimes of Richard Ramirez.

Richard Ramirez's victims During his violent crime spree, Ramirez committed 13 murders, five attempted murders, 11 sexual assaults and 14 burglaries. Here we list his murder victims.

Richard Ramirez, convicted of the "Night Stalker" serial murders in 1985, arrives at court in handcuffs and chains in Los Angeles on Wednesday, Oct. 4, 1989. Photo: Alan Greth/AP ...