S1·E5 – You Have to Dig

John Wayne Gacy

Self (archive footage)

Robert K. Ressler

Self - Ret. FBI Profiler (archive footage)

Terry Sullivan

Self - Fmr. Prosecutor, Cook County, IL

Craig Bowley

Self - John Gacy Prison Correspondent

Jay Levine

Self - Ret. News Anchor & Chief Correspondent

Rafael Tovar

Self - Ret. Des Plaines Police Detective

Lawrence Finder

Self - Fmr. Prosecutor, Cook County, IL

Karen Kuzma

Self - John Gacy's Sister

William Kunkle

Self - Fmr. Chief Prosecutor, Cook County, IL

Patti Szyc-Rich

Self - John Szyc's Sister

Jim Szyc

Self - John Szyc's Brother

Eugenia Godzik

Self - Gregory Godzik's Sister