Final answer:
Richard Ramirez, also known as the Night Stalker, became a serial killer due to a combination of several factors including a troubled childhood, fascination with Satanism, and mental health issues.
Step-by-step explanation:
Richard Ramirez, also known as the Night Stalker, became a serial killer due to a combination of several factors. One factor was his troubled childhood, which included exposure to violence and substance abuse. Another factor was his fascination with Satanism and the occult, which influenced his beliefs and behaviors. Additionally, Ramirez suffered from mental health issues, such as antisocial personality disorder and a potential brain injury, which may have contributed to his violent tendencies.