Parker is of over three quarters German descent (including ethnic Germans from Russia). One of his great-grandfathers was of Finnish origin, and he also has more distant Scottish and English ancestry.
Parker has two older sisters. One of them, Kelley Mack, is also an actress.
Parker did his own stunt work in Ouija 2 Origin of Evil.
Parker filmed the 3rd episode of the Chicago Fire episode, upside down in a van, teetering over Wacker drive in downtown Chicago.