December, 1978, police file photo
Charges: 33 murders
Gacy, one of the nation's most notorious and prolific serial killers, was convicted in 1980 of the murders of 33 young men and boys.
He buried most of their bodies in the crawlspace beneath his house in Norwood Park Township, an unincorporated area on the northwest edge of Chicago.
A building contractor who was active in local politics, Gacy sometimes performed as a clown at children's parties.
He had been killing for six years before he was arrested in December 1978 in connection with the disappearance of 15-year-old Robert Piest of Des Plaines. An honor student at Maine West High School, Piest had run into Gacy outside a local drugstore where Piest worked as a stock boy.
Piest's mother had gone to the drugstore to pick up her son to attend her birthday party. As she waited, Piest went outside to Gacy's car and was not seen alive again.
It was then that police began to take a serious look at Gacy. Eight days later, police began searching Gacy's home and found the remains of the first of 27 bodies buried in the crawlspace.Two other bodies were found buried in the back yard, and four, including Piest's, were found in the Des Plaines River.
Many of Gacy's victims were male prostitutes. He sometimes pretended to be an undercover police officer and would handcuff his victims as soon as they got in his car. He then drove them to his home, where the killings took place.
A jury convicted Gacy of all 33 murders on March 12, 1980, after deliberating for only two hours. The next day, the jury sentenced him to death after deliberating for two hours and 15 minutes.
In 1994, Gacy, then 52, was executed at Stateville Correctional Center in Joliet.