The bathroom mirror Michael Eklund cracked with his forehead in the fight scene with Sarah-Jane Redmond was real. Breaking it was not planned. The actors remained in character and continued with their performance, allowing the take to be used in the film.
When Sarah-Jane Redmond is walking alone through the parking garage, the operatic song heard is the Lord's Prayer in Latin.
The games room scenes were filmed in the basement of an abandoned psychiatric hospital.