Other mistake: When Ashley Judd is being chased by the killer she runs downstairs and hits her aquarium. In the first shot you see her turn her back and hit the aquarium, in the next shot you see her hit it with her shoulder.
Other mistake: In the Italian dub, Dr. McTiernan talks to the two Chinese women with both of them speaking the language, making the dialogue quite paradoxical (since the point of the scene is that the older woman speaks only Chinese and the other has to act as translator). Not just that, but she introduces herself as Dr. "McTiernenson", for the one and only time in the movie. (00:21:10)
Other mistake: The ambulance that picks up Jeremy Piven is from Santa Barbara, CA when the movie takes place in North Carolina. (01:13:23)
Answer: Unfortunately, a functioning psychopath might be able to pass a basic psych evaluation. There are several real life examples of serial killer policemen.
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