gunshots cruelly ended her plans. for police proving who murdered joan was a daunting task. an ominous killer was still out there, lurking and leaving joan's family living in fear. but they weren't the only ones whose lives might be in danger. here's keith morrison with "the threat." >> on the southern bank of the columbia river, tucked away in a corner of this little cemetery, is the final resting place of a woman called joan. barbara joan lockwood. she wasn't a famous woman, joan, wasn't rich or celebrated. she lived a quiet life in a quiet place, and was buried here three decades ago, but oh, if ghosts could rise from their graves, if joan could speak to us now, what questions could she answer?