Amy Ryan
Michelle McNamara's Words (voice) (7 eps)
Patton Oswalt
Self - Michelle's Husband (6 eps)
Michelle McNamara
Self (archive footage) (6 eps)
Paul Haynes
Self - Michelle's Researcher, Citizen Detective (6 eps)
Larry Crompton
Self - Ret. Detective, Contra Costa County (5 eps)
Melanie Barbeau
Self - Citizen Detective (5 eps)
Paul Holes
Self - Ret. Chief of Forensics, Contra Costa County (4 eps)
Karen Kilgariff
Self - Host, My Favorite Murder Podcast (4 eps)
Billy Jensen
Self - Crime Writer, Citizen Detective (3 eps)
Daniel Greenberg
Self - Michelle's Literary Agent (3 eps)
Kathleen Conroy
Self - Michelle's Sister (2 eps)
Mary Rita Skrine
Self - Michelle's Sister (2 eps)
Maureen Stratton
Self - Michelle's Sister (2 eps)
Bob McNamara
Self - Michelle's Brother (2 eps)
Kera Bolonik
Self - Michelle's Friend, Writer (2 eps)
Bonnie Colwell
Self - Joseph DeAngelo's Ex-Fiancée (2 eps)
Adam Drucker
Self - Michelle's Friend (1 eps)
Jennifer Barth
Self - Executive Editor, HarperCollins (1 eps)
Barbara Rae-Venter
Self - Investigative Genetic Genealogist (1 eps)
Gillian Flynn
Self - Author, Gone Girl (1 eps)
Wes Ryland
Self - Joseph DeAngelo's Nephew (1 eps)
Gay Hardwick
Self - East Area Rapist Survivor (1 eps)
Bob Hardwick
Self - East Area Rapist Survivor (1 eps)
Anne Marie Schubert
Self - Sacramento District Attorney (1 eps)
Michael G. Bowman
Self (1 eps)
Thien Ho
Self - Sacramento Deputy District Attorney (1 eps)
Chris Lombardo
Kathleen Lombardo's Brother (1 eps)
Tom Olis
Kathleen Lombardo's Neighbor (1 eps)
Kim Knebel
Kathleen Lombardo's Neighbor (1 eps)
Grace Puccetti
Self - Oak Park Attack Survivor (1 eps)
Kris Pedretti
Self - East Area Rapist Survivor (1 eps)
Linda O'Dell
Self - East Area Rapist Survivor (1 eps)
Jane Carson-Sandler
Self - East Area Rapist Survivor (1 eps)
Jennifer Carole
Self - Daughter of Murder Victim Lyman Smith (1 eps)
Debbi Domingo
Self - Daughter of Murder Victim Cheri Domingo (1 eps)
George Seibel
Self - Former Homicide Detective, Chicago Police Dept. (1 eps)
Lisa Ortiz
Self - Joseph DeAngelo's Cousin (1 eps)