John Wayne Gacy (March 17, 1942 – May 10, 1994) was an American serial killer and sex offender who raped, tortured, and murdered at least 33 young men and boys in Norwood Park Township, near Chicago, Illinois.

[26] In Waterloo, Gacy joined the local Jaycees chapter,[27] regularly offering extended hours to the organization in addition to the twelve- and fourteen-hour days he worked managing the restaurants.

Two doctors concluded he had an antisocial personality disorder (the clinical term for sociopathy and/or psychopathy), was unlikely to benefit from treatment, and that his behavior pattern was likely to bring him into repeated conflict with society.

[d] With financial assistance from his mother, Gacy bought a ranch-style house at 8213 West Summerdale Avenue in unincorporated Norwood Park Township, Illinois, part of metropolitan Chicago.

[48] Gacy was active in his local community and helpful towards his neighbors; he willingly loaned his construction tools and plowed snow from neighborhood walks free of charge.

[52][e] Carole observed Gacy bringing teenage boys into his garage in the early hours and also found gay pornography and men's wallets and identification inside the house.

His victims included people he knew and random individuals lured from Chicago's Greyhound Bus station, Bughouse Square, or off the streets with the promise of a job with PDM, an offer of drink and/or drugs, or money for sex.

According to Gacy's later account, following a family party the previous evening, he drove to the Civic Center in the Loop in the early morning to view a display of ice sculptures.

[86][87] Gacy took McCoy on a sightseeing tour of Chicago and then drove him to his home with the promise that he could spend the remainder of the night and be driven back to the station in time to catch his bus.

When his wife and stepdaughters returned home earlier than expected, Gacy buried Butkovich under the concrete floor of the tool room extension of his garage in an empty space where he had intended to dig a drain tile.

[130] Gacy drove him to his home, where he raped, tortured, and repeatedly drowned Donnelly to unconsciousness in a bathtub as he made statements such as, "Aren't we playing fun games tonight?

[146] This search revealed several suspicious items, including several police badges; a starting pistol; a syringe and hypodermic needle; handcuffs; books about homosexuality and pederasty;[147][148][149] pornographic and stag films; capsules of amyl nitrite; a dildo;[150] a two-by-four with two holes drilled into each end; bottles of Valium and atropine; several driver's licenses; a blue hooded parka;[146] and underwear too small to fit Gacy.

Surveillance teams (consisting of officers Mike Albrecht and David Hachmeister, and Ronald Robinson and Robert Schultz) monitored Gacy as the investigation continued.

[162] On the evening of December 20, Gacy drove to his lawyers' office in Park Ridge to attend a scheduled meeting, ostensibly to discuss the progress of his civil suit.

Gacy dismissed his victims as "male prostitutes", "hustlers" and "liars", adding he sometimes awoke to find "dead, strangled kids" with their hands cuffed behind their back.

On hearing from the surveillance detectives that, in light of his erratic behavior, Gacy might be about to commit suicide, police decided to arrest him on a charge of possession and distribution of cannabis in order to hold him in custody, as the formal request for a second search warrant was presented.

[173] After being informed that the police had found human remains in his crawl space and that he would now face murder charges, Gacy told officers he wanted to "clear the air".

[48] In the early morning hours of December 22, and in the presence of his lawyers, Gacy provided a formal statement in which he confessed to murdering approximately thirty young males—all of whom he claimed had entered his house willingly.

[48] Accompanied by police, his lawyers, and his older sister, Gacy was driven to the I-55 bridge on December 23 to pinpoint the precise spot where he confessed to having thrown the body of Robert Piest and four other victims into the river.

[57][177] Gacy was then taken to his house and instructed to mark his garage floor with orange spray paint to show where he had buried the individual he had supposedly killed in self-defense, whom he named as John Butkovich.

When Gacy had confessed to police, he claimed to be relaying the crimes of Jack, who detested homosexuality and viewed male prostitutes as "weak, stupid and degraded scum".

[66][165] On February 18, Robert Stein testified that all the bodies recovered from Gacy's property were "markedly decomposed [and] putrefied, skeletalized remains", and that of all the autopsies he performed, thirteen victims had died of asphyxiation, six of ligature strangulation, one of multiple stab wounds to the chest and ten in undetermined ways.

Prosecuting attorney Terry Sullivan outlined Gacy's history of abusing youths, the testimony of his efforts to avoid detection and describing his surviving victims—Voorhees and Donnelly—as "living dead".

[175] Amirante then urged the jury to put aside any prejudice they held against his client and asked they deliver a verdict of not guilty by reason of insanity, adding that Gacy was a danger to both himself and to others, and that studying his psychology and behavior would be of benefit to science.

[185] Kunkle referred to the defense's contention of insanity as "a sham", arguing that the facts of the case demonstrated Gacy's ability to think logically and control his actions.

[203] He drew inspiration from a wide range of sources for his artwork, depicting subjects as diverse as clowns (including himself as Pogo or Patches), Christ, the Seven Dwarfs, skulls, his own home, Elvis Presley, and John Dillinger.

[126][237] Body 9 (Timothy McCoy, identified via dental records and a distinctive belt buckle in May 1986) was found beneath a layer of concrete and had several stab wounds to the ribs and sternum, suggesting he was Gacy's first victim.

[106] He was buried directly beneath Body 21, recovered the previous day; this victim, who remains unidentified, is estimated to have been aged between 15 and 24 years old and approximately 5 ft 10 in (180 cm) in height.

[282] Shortly after his arrest, Gacy informed investigators that after he had assaulted and then released Jeffrey Rignall in March 1978, he began to throw his murder victims into the Des Plaines River.

[z][aa] Jeffrey Rignall, who had been assaulted and tortured by Gacy in March 1978, was adamant that at one point during his ordeal, a young man with brown hair had watched his abuse,[57] and that he saw a light come on elsewhere in the house.