tips about once a week, but most don't pan out. this one he feels especially good about, although he will not give us specifics. >> we'll pursue this lead until we find it is viable or a dead end. you try not to get too excited. it's difficult but you have to stay grounded because this lead could -- it could take us nowhere. >> reporter: working the case of a missing child is difficult even for the most hardened law enforcers. >> it is. i can't imagine if that was my child. i can't imagine the pain that her mother and stepfather must wake up with every day. i couldn't imagine that. >> that was her dog and that was her cat. >> reporter: today cherrie would be 34. if he's alive, this is what investigators think she might look like. >> she could be married and have children and have graduated and i could be a grandmother. >> reporter: after all these years, janice mckinney still