In this photo taken Friday, Nov. 30, 2012, in Chicago, Cook County Sheriff Tom Dart, left, and sheriff's detective Jason Moran are photographed with three recently discovered vials of mass murderer John Wayne Gacy's blood. The sheriff’s office is creating DNA profiles from the blood of Gacy and other executed killers and putting them in a national DNA database of profiles created from blood, semen, or strands of hair found at crime scenes and on the bodies of victims. What they hope to find is evidence that links the long-dead killers to the coldest of cold cases and prompt authorities in other states to submit the DNA of their own executed inmates and maybe evidence from decades-old crime scenes to help them solve their own cases. (AP Photo/M. Spencer Green)

This undated photo provided by the Cook County Sheriff's Department shows victims remains of serial killer John Wayne Gacy being exhumed by authorities. The Cook County Sheriff's Department last spring secretly exhumed the bones of the 8 victims who were never identified in the hopes that scientific tests that were not around between 1972 and 1978 when Gacy killed his 33 victims will make identification possible. (AP Photo/Cook County Sheriff's Department)

Serial killer John Wayne Gacy in 1978.

Will County Coroner Patrick K. O'Neil

Dart

FILE - This 1978 file photo shows serial killer John Wayne Gacy. Three vials of Gacy's blood were recently discovered by Cook County Sheriff's detective Jason Moran. The sheriff’s office is creating DNA profiles from the blood of Gacy and other executed killers and putting them in a national DNA database of profiles created from blood, semen, or strands of hair found at crime scenes and on the bodies of victims. What they hope to find is evidence that links the long-dead killers to the coldest of cold cases and prompt authorities in other states to submit the DNA of their own executed inmates and maybe evidence from decades-old crime scenes to help them solve their own cases. (AP Photo)

This photo taken Friday, Nov. 30, 2012, in Chicago shows three vials of mass murderer John Wayne Gacy's blood recently discovered by Cook County Sheriff's detective Jason Moran. The sheriff’s office is creating DNA profiles from the blood of Gacy and other executed killers and putting them in a national DNA database of profiles created from blood, semen, or strands of hair found at crime scenes and on the bodies of victims. What they hope to find is evidence that links the long-dead killers to the coldest of cold cases and prompt authorities in other states to submit the DNA of their own executed inmates and maybe evidence from decades-old crime scenes to help them solve their own cases. (AP Photo/M. Spencer Green)