In the summer of 1993, 34-year-old Greg Nicholson of Mason City, Iowa, vanished days before he was due to testify against his methamphetamine supplier. Nicholson had been arrested on federal drug charges and agreed to cooperate with authorities, a decision that preceded his disappearance on July 24, 1993. He left behind his girlfriend, Lori Duncan, and her two daughters, 10-year-old Kandace and 6-year-old Amber, who also went missing at that time.

Years later investigators located a shallow grave southwest of Mason City and recovered the bodies of Nicholson, Duncan, and the two children; investigators concluded they had been murdered. Evidence gathered in the investigation linked the killings to the supplier against whom Nicholson had agreed to testify and to an associate.

Did anyone in Mason City or the surrounding area have contact with Greg, Lori, or the children in late July 1993 that could shed light on their last movements?