When Jesse Hellman is parking near the art gallery, it is shown that the place is called "Belial." "Belial," in the Bible, is a demon of seduction, a creature that corrupts people and makes them go mad or behave badly towards others.
When Jesse meets Leonard at his house, he is wearing a t-shirt that says "Find what you love and let it kill you". This quote is from Charles Bukowski's memoirs: "My dear, Find what you love and let it kill you. Let it drain from you your all. Let it cling onto your back and weigh you down into eventual nothingness. Let it kill you, and let it devour your remains. For all things will kill you, both slowly and fastly, but it's much better to be killed by a lover. Falsely yours, Henry Charles Bukowski"
Pruitt Taylor Vince originally turned down the role of 'Ray' as he was receiving an abundance of mad/villainous roles, but Byrne wrote him "an impassioned letter" explaining how he needed someone capable of playing "the lost child trapped inside the monster." It worked.
From the Hebrew 'Bliol', meaning Wicked One, in demonology Belial is one of Satan's most venerable demons. In fact, before the New Testament firmly established Satan as the leader of the forces of evil, Belial was the one in charge. In the Old Testament the word had the meaning of worthlessness or wickedness, but it later came to be used as a proper noun for the Devil or Satan.
The film was introduced to a live audience by lead actor Ethan Embry at Horrorhound Cincinnati, Ohio on March 18th, 2017. Ethan stated this film was more in line with his own tastes and that is was "a family movie" in regard to the focus on family bonds.