Continuity mistake: When Lynn first finds out about the Olson murders, their house is two doors down from where she is house sitting. Later on, when Detective Peters mentions the murders in passing, he states that their house was three doors down.
Plot hole: After the police discover the plot to kill Lynn by her ex-husband, they never bother to visit his house to arrest him. If they did, they would have found him dead already and would have KNOWN that the killer was still at large.
