Factual errors: After the police find the blood under the floor boards in Fernandez's house, we hear Hildebrandt's voice-over that the cops just missed the couple as they were 5 miles away in Seaford, NY buying a flop top car. Fernandez's home was in Valley Stream which is close to 20 miles away from Seaford, not 5 miles.
Continuity: About 25 minutes into the movie Elmer Robinson and Charles Hilderbrandt have a talk in the parking garage. Elmer gets into the car and slams the door shut. In the next scene the door is still open as the two continue their discussion.