The film takes place in the same universe as the films "Training Day" and "Harsh Times," all written by director David Ayer. The Blood gang member character "Bone" (portrayed by Cle Sloan) appeared in Training Day. The film also references the existence of the fictional Latino gang "Hillside Trece," which was the gang Alonzo Harris had dealings with in Training Day, and the gang is mentioned in Harsh Times as well.
Shia LaBeouf had his entire chest tattooed in preparation for the role of Creeper, the "tax collector."
This is Shia LeBoef and David Ayer's second collaboration after Fury (2014).
Shia LaBeouf has caulifower ears on his ears to indicate that he is an experienced fighter.