Cassidy Freeman wore a piece of make-up and padding on her abdomen, to make her look pregnant. She would often stash snacks in it.
The film is dedicated to the memory of Mexican journalist León García Soler (who died on December 11, 2020), and his wife Andrea Valeria (who died on September 10th, 2019). In the film the President of México is named after García Soler.
There is a Wilhelm scream at 1:30:36.
'The Forever Purge' director Everardo Gout thinks that if aliens were to come down to earth, The Purge (2013) "would be one of the 10 films that represent who we are."