I'm going to guess Looker (1981)
Dr. Larry Roberts (Finney), a Beverly Hills plastic surgeon, is puzzled when four beautiful models working in television commercials request cosmetic surgery to make changes so minor as to be imperceptible to the naked eye. When these models later start dying under mysterious circumstances, he discovers they are all linked to the same advertisement research firm.
The Digital Matrix research firm rates advertising models using a scoring system to measure the combined visual impact of various physical attributes in television commercials. In an experiment to increase their scores, some models are sent to Dr. Roberts to get cosmetic surgery to maximize their visual impact. Though the models are physically perfect after the surgery, they still are not as effective as desired, so the research firm decides to use a different approach. Each model is offered a contract to have her body scanned digitally to create 3D computer-generated models, then the 3D models are animated for use in commercials. The contracts seem to be incredibly lucrative for the models; once their bodies are represented digitally, they get a paycheck for life, never having to work again, since their digital models are used for all their future work in commercials.
However, when these same models start dying under mysterious circumstances, Roberts becomes suspicious and decides to investigate Digital Matrix. He has a strong interest in investigating the deaths: he is considered a prime suspect by the police (from evidence planted at the scene of one of the murders) and his most recent patient, (with whom he is in a relationship) Cindy (Susan Dey). Cindy is the last of the models to be digitally scanned.
During his investigation, Roberts discovers some advanced technology that the Digital Matrix corporation is using to hypnotize consumers into buying the products they advertise. He also discovers the Light Ocular-Oriented Kinetic Emotive Responses (L.O.O.K.E.R.) gun, a light pulse device that gives the illusion of invisibility by instantly mesmerizing its victims into losing all sense of time.
Found by searching for
film murder "actors replaced * computers", which took me to the Wikipedia entry for Virtual actor, which mentions Looker.
This review mentions the falling death:
.... Stalked by a shadowy figure hiding behind her curtains, Lisa (Terri Welles) falls to her death from the balcony of a glass-laden apartment after being inexplicably frozen by some sort of unseen interval-halting firearm.