• 
  Dion Graham

  Himself - Narrator (voice)
• 
  Josephine Rene

  Jane Doe
• 
  Woody Andrews

  Inmate Rosdale
• 
  Jeff Hancock

  Himself - Edmond Police Department (as Det. Jeff Hancock)
• 
  Mike Riley

  Himself - Gary's Friend
• 
  J. Douglas Perkins

  Himself - Criminalist Supervisor, OSBI
• 
  Kenny Catlett

  Himself - Gary's Friend
• 
  Stephen Day

  Himself - Edmond Police Department (as Det. Stephen Day)

• 
  Chuck Goode

  Himself - Edmond Police Department (as Det. Chuck Goode)
• 
  Jim Stokes

  Himself - Criminalist Supervisor, OSBI
• 
  James Hamm

  Himself - Edmond Police Department (as Officer James Hamm)
• 
  Gary Larson

  Himself - Victim (archive footage)
• 
  Greg Elwell

  Himself - Former Reporter, Daily Oklahoman
• 
  Jonathan Graham

  Himself - Suspect (archive footage)
• 
  Dianne Clary

  Herself - Gary Larson's Sister