and i won't let it go. >> reporter: lisa peebles and, most of all, gary thibodeau and his family lostgoing to keep on fighting for him. >> reporter: lisa is appealing to an even higher court. and as for tonya? >> what do you do? you just keep fighting. >> reporter: oddly maybe, those two families, the thibodeaus and the allens, divided as to guilt and innocence, both all these years later have the same question -- what did happen to heidi, and will we ever find a shallow grave? >> i think, eventually. >> eventually something's going to happen. someone's going to say something. >> i might not know on this side of heaven. i might have to wait. but i will die trying and fighting for her. >> reporter: she went to work early on an easter sunday morning and was never seen again. >>> that's all for this edition of "dateline." we'll see you again sunday at 7:00, 6:00 central for "on assignment" and then for "dateline" at 10:00, 9:00 central. i'm lester holt. for all of us at nbc news, good night. >>> nbc 10 breaking news. >> we begin with this breaking news in chester county tonight. skyforce