In 1972, Speck’s death sentence was commuted to 50 to 100 years in prison, when the US Supreme Court abolished capital punishment. Having served 19 years of that sentence, he died of a heart attack on 5 December 1991.
Speck was never officially charged with the murders of which he was suspected, prior to the events that took place in the South Chicago townhouse and officially those cases remain unsolved.
In 1996, five years after Speck's death, a television journalist made public a prison video, which showed Speck taking drugs and engaging in sex with another inmate during the 1980s, whilst he was an inmate at Statesville Correctional Institute; Speck appears to have breasts in the video, apparently as a result of hormone treatment received whilst in prison, and is wearing women’s underwear. In the video, Speck also casually admits to the killing of the nurses, describing the strangulations in some detail, and bragging about the strength required to kill someone in this manner.
The video’s release caused a major scandal within the Illinois Department of Corrections and was widely cited as justification for the reintroduction of death penalty.