The Case of Robert Jerome Piest

Robert Jerome Piest, 15, disappeared on December 11, 1978, after telling his mother that a contractor at the pharmacy where he worked had offered him a summer job. That contractor was John Wayne Gacy. Robert left the pharmacy expecting to meet Gacy and never returned. His disappearance triggered the investigation that ultimately exposed Gacy as a serial killer and led police to the bodies concealed beneath his home.

Robert Piest was 15 years old and lived with his family in Des Plaines, Illinois. He was a high-school student who worked part-time at a local pharmacy. On December 11, 1978, Robert was working at Nisson Pharmacy in Des Plaines. Gacy was at the pharmacy that afternoon because his construction company had been working on the building. Gacy approached Robert and reportedly offered him a job for the following summer. Robert told his mother that a contractor had offered him work and said he wanted to speak with the man before she picked him up. When Robert's mother arrived at the pharmacy, she was told that he had left to speak with the contractor. Robert never came home. Unlike many of Gacy's earlier victims, Robert's disappearance immediately generated an intense investigation because his family knew precisely where he had been shortly before disappearing and Gacy's presence at the pharmacy was quickly established.

Robert was murdered by Gacy after being lured away from Nisson Pharmacy. His body was ultimately disposed of beneath Gacy's home at 8213 West Summerdale Avenue in Norwood Park Township. Investigators recovered Robert's remains during the excavation of Gacy's property in December 1978. His body was discovered in the crawl space after police had already begun uncovering evidence of multiple murders. Robert was the final known victim of Gacy's murder spree.

Robert's disappearance triggered the investigation that finally brought Gacy's crimes to light. Des Plaines police immediately began investigating Robert's disappearance. Because Robert had told his mother that a contractor had offered him a job, detectives traced the contractor to Gacy. Investigators questioned Gacy about Robert and examined his background. Gacy initially denied any involvement and attempted to provide an explanation for Robert's disappearance. Police nevertheless continued investigating him. Surveillance was established, and investigators began examining Gacy's movements and property. The investigation eventually led police to search Gacy's home. During the search, officers discovered suspicious materials and evidence indicating that human remains were buried beneath the house. The discovery transformed the investigation. Excavation of the property uncovered the remains of numerous young men and boys. Investigators ultimately recovered 29 bodies or sets of remains from Gacy's property, while additional victims were recovered from the Des Plaines River and other locations. Robert's disappearance therefore became the case that unravelled the entire Gacy murder investigation.

John Wayne Gacy was arrested in December 1978 and subsequently charged with 33 murders. He was convicted of murdering Robert Piest and the other 32 victims in 1980 and sentenced to death. Gacy was executed by lethal injection at Stateville Correctional Center on May 10, 1994. Robert's remains were recovered during the investigation of Gacy's home and were eventually identified through forensic evidence.

Robert Piest was Victim 28 of 33 in our chronological CrimeTrakr sequence and Gacy's final known victim. Robert's disappearance was different from most of the earlier cases because investigators were able to establish a clear last known encounter with Gacy almost immediately. That allowed police to focus on Gacy before he could continue killing. The investigation into Robert ultimately revealed that Gacy had been murdering young men and boys for years and concealing their bodies beneath his home. Robert's case therefore represents the turning point between Gacy's hidden murder spree and the discovery of the full extent of his crimes.