I remember seeing this film, written and directed by Michael Crichton, as a child. I remember it as the only movie that scared the daylights out of me and gave me nightmares. So I decided to rent it as an adult and see WHY it scared me so much as I only remembered a few scenes from the film.
Tom Selleck plays police sergeant Jack Ramsay, whose job is to stop machines that have circumvented their programming and become dangerous. Runaways. In the process of investigating a few runaways, he discovers that the machines aren't runaways at all. A chip has been inserted that turns them into killing machines.
While the acting is often over the top (or, in the case of Ramsay's son, underacted), and the special effects cheesy by today's standards, the plot holds. As does the creepiness of seeing spider like robots jump on people and stab them in the throat with needles (the scenes that creeped me out as a kid).
Crichton had no problem killing characters either, which made watching this a real edge of my seat experience.
Here's the movie trailer: