without solid evidence horry county was forced to set bambi bennett free. despite bambi refusal to testify against her boyfriend, prosecutors believed this they had enough evidence to bring rick gagnon down. including a a surprise witness. here is more of "the deed." >>> reporter: rick gagnon was in a world of pain. locked up in the county jail facing two murder charges. he shared his woes with another guy in a jumpsuit, two inmates power walking together around the yard. >> we would walk around the -- the -- the pod, do laps. >> reporter: the jail yard buddy was named robert mullins, a petty crook who seemed strangely interested in rick's troubles. >> reporter: did he want to talk to you about the case? was he grilling you? >> yeah, all the time. all the time. >> reporter: but then, it seemed everyone in this part of south carolina wanted to know more about the case and its two beloved victims. it took three years, but in 2008 the state was ready to try rick gagnon for the murders of charlie and diane parker. a camera was rolling as prosecutor fran humphrie