Cody Dial

A memoir by Roman Dial details the scientist and National Geographic Explorer's journey following his son's disappearance in Costa Rica. 

Roma and Luda Gimelfarb are in Costa Rica this week for what's become a tragic, annual ritual: searching for information about their son, David, who went missing in Rincón de la Vieja National Park in Guanacaste seven years ago today.

A criminal investigation has been underway for several months but OIJ officials said the location of the body makes foul play unlikely.

The documentary series, "Missing Dial," follows Roman Dial's eight-month search in Costa Rica, accompanied by private investigators. Among the theories for his disappearance, the show will examine the dark rumors swirling around the remote Osa Peninsula that Cody Dial was murdered.