48 HOURS MYSTERY: AN EXTRAMARITAL AFFAIR TURNS INTO A SHOCKING DOUBLE MURDER IN A SMALL SOUTHERN TOWN "FAMILY AFFAIR" SATURDAY, JULY 14 (10:00 PM ET/PT)

Robin Heidt had a secret that, once exposed, wrecked the lives of her family and rocked Springfield, Georgia. As Susan Spencer reports in this updated edition called "Family Affair," the Southern family looked perfect to outsiders, but inside was a ball of tension over what Robin had hidden from the rest of them. It was the kind of story that keeps Hollywood filmmakers in business, but this was no film, it was real life. Indeed, Robin's secret was so explosive that the revelation ended up leading to the death of two family members, left another severely injured and ended with one convicted of murder. "I had a secret... and once it was exposed, all hell broke loose," Robin tells Spencer in her first national TV interview.