WAS A HIGH SCHOOL SOHPHOMORE BRAINWASHED INTO VICIOUSLY KILLING HIS FORMER BEST FRIEND, OR WAS HE THE MASTERMIND?, ON ABC NEWS' "PRIMETIME CRIME," WEDNESDAY, AUGUST 19

How far would an innocent high school student go to try to fit in? Isaac Grimes is serving a 60-year sentence for viciously killing his onetime best friend, Tony Dutcher, as well as Tony's grandparents when he was only 15. How did an apparently normal, innocent looking teenager in Colorado Springs, Colorado get involved in something so horrible? Grimes speaks out for the first time to Jim Avila, saying he did it because of a twisted version of the children's game Simon Says. The report airs on "Primetime: Crime," WEDNESDAY, AUGUST 19 (10:00-11:00 p.m., ET) on the ABC Television Network.

In the fall of 1999, Grimes entered his freshman year at Palmer High School. The lonely boy crossed paths with a charismatic high school senior named Simon Sue. The upperclassman took Grimes under his wing and eventually offered him a chance to join his club, called the O.A.R.A., or the Operations and Reconnaissance Agents. For a young boy desperate to have connections with others, hanging out with Sue and being invited to join the O.A.R.A was everything he desired -- at first.

But Grimes and his so-called band of brothers would quickly move on from fun, harmless activities like chess to much more dangerous ones. Grimes claims that Sue took the boys to a local range to practice shooting weapons, and he taught them how to disassemble and clean the firearms. All of this was supposed to be part of their training in preparation for their larger mission: To be prepared to fend off a coup in the Sue family's native land, the small South American country of Guyana. He tells Avila that Sue had essentially been brainwashing him.

Grimes says that when Sue ordered him to "prove his loyalty" by not just committing murder, but by killing his former best friend, Tony Dutcher, the younger boy readily agreed. Grimes viciously sliced Dutcher's throat, nearly decapitating him in the process. Dutcher's grandparents, Joann and Carl Dutcher, were also found shot to death in their home in early 2001. But as Avila unravels details about the case and Simon's bizarre group, the truth about this unspeakable crime become even murkier. Could it be that Grimes was the real mastermind and Sue was another victim?

David Sloan is the executive producer of "Primetime: Crime."