Nicki Myers Bates was just 7 years old in 2006 when her mother vanished and the man her mom lived with told police he watched her die. That man, William Greer, went on the run, evading authorities for years. Nearly two decades later, Bates is still desperately trying to find her mother's remains.

Help solve a murder case: a former model brutally killed in her Georgia home. Someone out there knows something ... is it you? "48 Hours" correspondent Erin Moriarty investigates