1. He was relentlessly mocked, humiliated, and abused by his father while growing up.

Like many serial killers, Gacy grew up in an abusive home. Though he was close to his mother and two sisters, Gacy’s father attacked him, verbally and physically, from the start. Gacy’s father called his overweight, uncoordinated son a “sissy” and a “f*ggot,” insisting that the boy would inevitably be a disappointment. Of course, Gacy grew up desperately trying—and failing—to please this cruel man. He also internalized his father’s homophobia, which later manifested in bizarre forms of self-denial and self-hatred. In the same breath, Gacy would assert how much he loathed “f*gs,” then describe his sexual encounters with other men. Related: Inside the Demented Mind of John Wayne Gacy, Jr.

2. He worked as a mortuary assistant.

During his three months in that role, Gacy slept on a cot behind the embalming room. Gacy would later admit that he got inside a coffin with the embalmed corpse of a young man one night, kissing and caressing it.

Photo Credit: Murderpedia

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3. Gacy served an 18 month sentence for sodomy in the 1960s.

In 1967, Gacy sexually assaulted a 15-year-old boy, the son of one of his friends from a political club. He was ordered to undergo a psychiatric evaluation after charges were brought against him. Gacy was diagnosed with antisocial personality disorder, and one psychiatrist noted his intense inability to take responsibility for his actions: He vehemently denied everything, claiming he had been a victim of circumstance. Gacy was sentenced to 10 years in prison but only served 18 months, as he was a model prisoner during his incarceration.

4. Gacy called his friend for legal advice in 1978. That friend was lawyer Sam Amirante, who went on to represent Gacy when he was charged and convicted of 33 murders in 1980

‘”Sam, could you do me a favor?’ A telephone call, seven short words, a simple-enough request. That’s how it all began,” writes Amirante in his chilling memoir John Wayne Gacy: Defending a Monster . Related: 10 Little-Known Facts About Jeffrey Dahmer

5. He admitted everything.

One night, a wildly-intoxicated Gacy called an emergency meeting with his lawyers. Over the course of the night, he proceeded to drunkenly, and casually, as if telling a banal story, recount the rapes and murders he had committed over the past decade, claiming the body count was probably around 30. Amirante wrote that watching Gacy admit to murdering dozens of men as nonchalantly as he might recall the events of a football game shocked him to his core.

Photo Credit: Wikipedia

6. He painted clowns in his prison cell.

During his 14 years on death row, Gacy painted, and clowns were one of his most common subjects. Until 1985, Gacy was actually able to earn money from selling these paintings.

7. His last meal before being executed was…

A bucket of Kentucky Fried Chicken, a dozen fried shrimp, french fries, strawberries, and a diet coke. Related: No Seconds: The Last Meals of Death Row Inmates

8. His final words were…

“Kiss my ass.”

9. Gacy’s crimes helped inspire the creation of what is today known as an Amber Alert

In 1984, Amirante created the Missing Child Recovery Act. Prior to this legislation, Illinois authorities had to wait 72 hours after a child was reported missing before beginning a search. Amirante’s legislature removed this 72 hour waiting period, allowing authorities to begin searching right away. Other states adapted similar laws, and a nationwide network for missing children was gradually formed, today known as the Amber Alert System.

Read more about John Wayne Gacy and Sam Amirante, the man who defended him, in John Wayne Gacy: Defending a Monster.