According to director James DeMonaco, the famous road-rage incident awakening the idea for The Purge happened like this: He and his wife were driving on the freeway when a drunk driver cut them off nearly killing them. After both cars stopped, the other driver's lack of remorse enraged DeMonaco enough to engage in a fistfight and police eventually had to get involved. After the incident was over, DeMonaco's wife turned to him and commented how great it would be to have one free murder a year. He felt bad admitting this because she's normally a "sweet woman".

For a while in the middle of the movie, James has a shaped goatee and moustache, which he does not have during the rest of the movie.

At the end Credits there are radio broadcasting about the Purge Night.

Edited into Everything Wrong with...: Everything Wrong with The First Purge (2018)