Love is in the air on Valentine's Day, but this special Crime Stories episode reminds us of how the passion can turn into poison. What lessons has Nancy Grace learned after many years as a prosecutor and then as a TV host covering cases of love gone bad? She discusses those lessons with Dr. Brian Russell, a lawyer and psychologist who hosts Investigation Discovery's "Fatal Vows" series, Cold Case Research Institute director Sheryl McCollum, lawyer & child advocate Ashley Willcott, and RadarOnline.com reporter Alexis Tereszcuk.