. >> reporter: detroit private eye julianne cuneo had been baffled for years about the mystery of theld man bob. the murder that put tommy and ray hyers in prison for life. late in the blue in late 2010, because some woman had a moment of nostalgia and posted a casual note on facebook, an affidavit landed on julie ann's desk from a man she never heard of, john hielscher. >> it had to be real. it had to be true. >> like a piece of heaven falling down in your lap. >> yeah. >> reporter: john told julianne what happened that awful night in the summer of 1987. it was party night, he said. john and his classmates just graduated from grosse pointe north high school. that's in the suburb where the captains of industry lived. several miles and tax brackets across the city line of detroit. and after a few beers, the partiers decided to drive over and buy some marijuana from old man bob. >> you just call up, say you're coming by, go to the back door. there. that's what we were going to do that night. >> reporter: jon and four friends jumped in a car, a white plymouth horizon and drove over to ma