Sentence:  Motion picture <WSD>cameras</WSD> had been installed to film the audience , the reservation list was being checked out name by name , and a special detail was already at work in the parking lot scrutinizing automobiles for a possible lead . 
Meaning of the word marked with <WSD> tags:  equipment for taking photographs (usually consisting of a lightproof box with a lens at one end and light-sensitive film at the other)