I saw this film in the early 80s. Italian language with subs. A murder is committed in a cinema. The police arrive and begin to investigate. They decide to re create the situation, turn lights out, etc. Low and behold, someone else is murdered. Please, if anyone knows this film it would mean a lot to me. TA.
“Closed Circuit”(1978 TV Movie) Italian title “Circuito chiuso”
http://www.imdb.com/title/tt0077337/?ref_=tt_urv
You can watch full movie here: