 The filmmakers used two different shopping malls for the scene where  the doctor injects Tuck into Jacks rear. The opening scenes where  the doctor runs in and heads for the elevator were shot in the  Northridge Mall in the San Fernando Valley in Los Angeles (also the  epicenter of the 94 quake). The scene where he reaches the top and  rams the syringe into Jack was filmed on the top floor of the  Sherman Oaks Galleria, another mall several miles away.