By Reason of Insanity

Terry Sullivan

Self - Fmr. Prosecutor, Cook County, IL

John Wayne Gacy

Archive footage

Jay Levine

Self - Ret. News Anchor & Chief Correspondent

David Hachmeister

Self - Ret. Des Plaines Police Officer

Anthony Antonucci

Self - Former Gacy Employee

Rafael Tovar

Self - Ret. Des Plaines Police Detective

Lawrence Finder

Self - Fmr. Prosecutor, Cook County, IL

Michael Albrecht

Self - Ret. Des Plaines Police Officer

Karen Kuzma

Self - John Gacy's Sister

William Kunkle

Self - Fmr. Chief Prosecutor, Cook County, IL

Ray Cornell

Self - John Gacy's Former Friend

Patti Szyc-Rich

Self - John Szyc's Sister

Eugenia Godzik

Self - Gregory Godzik's Sister

Ron Wilder

Self - Jeffrey Rignall's Partner

Sam Amirante

Self - Gacy's Attorney (archive footage)