A number of items in the hotel would not have been present in 1966. These include electronic card locks on the room doors, as well as a fax machine, a computer screen, and a laser-printed sign behind the front desk.
When Speck is riding the train, we hear sounds as if the train is passing railroad crossings. However, by looking at the windows we can tell that the train is not moving.
Richard Speck: I tell ya, I might just have to move to Washington, DC, they got a hell of a crime rate there. That might be just the town for a guy like me.