Goofs

When Joe leaves his apartment to go to Dave's apartment, he leaves his hat behind. When he later leaves Dave's apartment, he has his hat.

At the end of the film, Leland is driving on a bridge, his car surrounded by other vehicles, both alongside and behind. When the scene cuts to a long shot of Leland's car, all the other traffic has vanished.

When Leland is in the restaurant with Mrs. MacIver, there are fruit cups in front of them. After Karen leaves them, there are pies.

Leland is searching Dr. Robert's office when the doctor walks in. A few minutes later, they're in the doctor's house on the beach.

NYPD detectives investigating a murder scene always have their shield displayed, but none of the detectives are wearing one.

When Sgt. Leland is examining the murder scene, he carefully opens the medicine cabinet with a pen. But when he looks into the closet, he handles both a dumbbell and the container of mineral oil, thus compromising any fingerprint evidence.

When Joe is depicted first visiting the beach house of Dr. Roberts, the view in the distance is of the California coast. The film takes place in and around New York City and Long Island.

The racetrack where MacIver commits suicide clearly is the Garden State Park Racetrack - a now defunct track located in Cherry Hill, New Jersey. Thus, New Jersey authorities would investigate the death, not the New York City police.

In the credits, the last name of William Windom's character is spelled "MacIver". However, on the envelope containing his taped confession, Dr. Roberts has spelled it "McIver".