Goofs

Although the film takes place in the late 1970s, Many of the fashions, hairstyles, and cars are from the late 80s early 90s.

Kozenczak calls the Kodak place where the roll of film was sent for development. A sign identifies it as a "Film Centre". "Centre" is the Commonwealth spelling of the word that Americans spell "Center." This miniseries was filmed in Toronto.

One of Gacy's potential victims is shown wearing a Michael Jordan t-shirt. Jordan would have been a junior in high school at the time of the murders.

A Ryne Sandberg Cubs poster is hanging on the wall. At the time of the murders, Sandberg was with the Philadelphia Phillies. He didn't come to the Cubs until 1982.

In the scene where the detective is confronting Gacy, the first time while Gacy has his back to the bar, you can see the mike and boom at least on three different cuts.