Russell Hill and Carol Clay didn't deserve to die. Four years ago, on a camping adventure in Victoria's remote high country, they had a chance encounter with Greg Lynn. Only he now knows the precise details of what happened, but there was a dispute that turned violent. The couple, both in their 70s, were killed. Last Tuesday, in an unusual verdict, a jury found Lynn guilty of murdering Carol though not guilty of murdering Russell. But the conviction of the former Jetstar pilot does not mean it's case-closed just yet. On 60 Minutes, Sarah Abo reveals disturbing secrets about Greg Lynn's past that authorities need to investigate further.