Visible crew/equipment: Michael Douglas spots Sharon Stone's car after the high-speed highway chase and as he walks up to her you can see the reflection in his sunglasses of the cameraman walking in front of him. (00:42:10)
Visible crew/equipment: Jeanne Tripplehorn along with Dr. Myron and Dr. McElwaine meet with Michael Douglas back at the station after Roxy's death and equipment shadows can be seen moving all over the walls. (01:28:00)
Visible crew/equipment: As Roxy follows Michael Douglas after he leaves Mac's Diner, the shadow of the cameraman can be seen moving on the license plate of Sharon Stone's car. (01:23:45)
Visible crew/equipment: At the beach house, Sharon Stone and Michael Douglas speak about Jonny Boz and as she says, "I wasn't dating him" the shadow of the cameraman can be seen moving on the railing behind her. (00:11:20)
Visible crew/equipment: Michael Douglas spots Sharon Stone's car in front of Hazel Dobkins' house and if you look closely as he walks up to her car you can see the camera man's reflection on the front window as he is obviously filming inside of another vehicle. (00:42:00)
Visible crew/equipment: The film crew is visible in Nick's sunglasses when he meets Hazel, the old lady.
Visible crew/equipment: After the scene in Jeanne Tripplehorn's apartment, Michael Douglas meets with the other investigators back at the police station and the reflection of the cameraman can be seen in the glass partition behind him as an investigator says, "I made a couple of calls to Berkeley." (00:38:45)
Visible crew/equipment: When Michael Douglas pulls his car in front of Jonny Boz' house after the initial murder scene policemen on the far corner can be seen directing traffic away from the movie set, at the top of the hill. (00:04:10)
Visible crew/equipment: Michael Douglas kisses Jeanne Tripplehorn in her apartment and the shadow of the camera can he seen on his shirt in the extreme close ups. (00:36:00)
Answer: No definitive answer is given in the film. Catherine didn't need a reason for anything that she did. As for Beth, that was just a bonus, or a coincidence. It could be argued that Catherine targeted Beth, and Nick was just unfortunate to be involved with Beth.
ChristmasJonesfan