The remains of eight unidentified victims of John Wayne Gacy, serial killer and sometime party clown, have been secretly exhumed for DNA identification.

U.S. news media reported that the Cook County Sheriff's Office wished to DNA test the remains and identify eight unidentified victims, who had been buried in Chicago-area cemeteries with grave markers inscribed with "We Remembered."

The remains were recovered from a Chicago-area home owned by Gacy, convicted of the sexual assault and murder of 33 boys and young men in the 1970s.

Gacy, who performed at children's parties and charity events dressed as a clown, was arrested in 1978 and put to death in 1994.

Cook County has been working with the University of North Texas Center for Human Identification to obtain DNA from the jaw bones of four victims and the femurs of four others, the Chicago Sun-Times reports.

CNN quotes Sheriff Tom Dart reportedly said: "These were eight young men with futures, and one of the most evil people to ever be on this planet destroyed their lives."

"These are eight people who deserve more," he added, according to the Sun-Times.

DNA samples shows that the eight victims were white males aged between 14 and 32, CNN reports, adding that the authorities have even listed the approximate dates of their disappearances.

Relatives of young men who disappeared in the 1970s have been urged to undergo a saliva test to help determine any DNA link to the skeletal remains, the LA Times reports.

Detectives told the Associated Press that the passage of time might actually work in their favor: Some families who never reported the victims missing and never searched for them could be willing to do so now, a generation after Gacy's homosexuality and pattern of preying on vulnerable teens were splashed across newspapers all over the world.