Robert Jerome Piest was a 15-year-old high school student and part-time worker at Nisson Pharmacy who disappeared from Des Plaines, Illinois, on December 11, 1978. He told his mother he was going to speak with a contractor about a possible job; that contractor was John Wayne Gacy, who lured Piest to his home and later confessed to suffocating him with a rope while the teenager was reportedly terrified and crying.

Gacy kept Piest’s body in his house for two days before disposing of it in the Des Plaines River because the crawl space where he had buried many victims was full. Evidence linking Gacy to Piest, including a film receipt belonging to Piest’s coworker found in Gacy’s home, contradicted Gacy’s initial claim that he had never met the boy. The investigation into Piest’s disappearance led to Gacy’s arrest on December 21, 1978, and to the recovery of many victims’ remains; Gacy was charged with the murders of 33 young men and boys, convicted in 1980, and sentenced to death.

Piest’s disappearance and death were pivotal in uncovering the full extent of Gacy’s crimes and highlighted failures in recognizing patterns in missing young men at the time. If anyone knew Robert Piest, worked with him, or has information about his last movements on December 11, 1978, please come forward.