Seven years before production, 14-year-old Holger Thaarup of Denmark was originally cast as the lead, Blake. He didn't speak any English and Gus Van Sant intended the role to be silent; Van Sant then met 17-year-old Michael Pitt and cast him instead.
One of the LDS missionaries that visits the house is wearing a light blue shirt. LDS missionaries are only permitted to wear non-decorative white shirts with dark pants/suits, and a conservative tie. The missionaries also carried no pamphlets, visual aids, appointment books, or their own complete sets of scriptures, which is highly unlikely for door-to-door proselytizing.