FBI Special Agent Jonathan Grusing. (Marty Caivano/Camera)

After Bob Marcum and Rob McLeod meet with the FBI about their missing daughters, Special Agent Jonathan Grusing is assigned to investigate the missing-persons cases surrounding Scott Kimball.

Working with Lafayette police detective Gary Thatcher, Grusing launches an exhaustive investigation, looking for clues that Kimball had transitioned from a white-collar criminal to a serial killer.