Goofs

When Rodney falls while dancing with the skeleton, first it's on top of him, then it's to his side, and then it's on top of him again.

When Dahmer is attacking his first (chronological) victim, Dahmer's left hand is alternately grasping/not clasping his victim's jersey between shots.

When Lance is on top of Jeffrey and choking him, his hand changes position on Dahmer's neck between shots.

When Rodney is seducing Dahmer and draping the belt around his neck, the buckle moves from the left and right side of his neck between shots.

When Dahmer is sitting in the lunch room of the chocolate factory, the establishing shot shows three chocolate men standing in a row in front of him. In the next shot, the chocolate figure on the right has fallen down.

The opening title card indicates that Jeffrey Dahmer was sentenced to 957 years of federal prison. This is inaccurate. Dahmer was convicted of 15 murders in a state trial in Wisconsin and served his sentence at Columbia Correctional Institution, which is overseen by the Wisconsin Department of Corrections.

The uniforms for the Milwaukee Police officers are incorrect. The badges and cap shields are L.A. style and the officers are wearing shoulder patches on both shoulders. Milwaukee officers wear a patch only on the left shoulder.

When Dahmer gets pulled over by the cop in 1978, he shows a New York State driver's license from post 1995.

The film depicts Milwaukee Police in a black and white car. Milwaukee police at that time drove solid white cars and did not go to black and white until 2008.

In the flashbacks of 1978 Dahmer is driving a mid 1980s Chrysler wagon.

At the end when Dahmer and Rodney are fighting, Rodney's wife beater changes from white to red and back to white again.

During the scene where Jeffrey is about to purchase a knife in the sporting goods store, a boom microphone is visible at the top-center of the screen. This occurs right after the store clerk says "I ain't even messin' it up."