Intruder is a 1989 horror film written and directed by Scott Spiegel, and cowritten by Lawrence Bender.
The owners gather the night crew to announce they are selling the store and the staff will soon be out of a job. The employees are assigned the task of marking down all the stock in preparation for the close. Craig makes telephone calls to the store, unnerving Jennifer. The police arrive but do little to help, and just tell the group to be careful.Finishing her shift, Linda is stabbed and killed by an unseen attacker. Bill spots someone trying to enter through the back door and goes out to investigate. He finds Craig watching Jennifer through the bathroom window and is hit on the head with a hammer. Back in the store the unseen assailant stalks the employees and kills them one by one. The assailant attacks Danny from behind before pushing his eyes through a bill spike on the desk. The assailant rams a chefs knife through Produce Joes head, splitting it. The murderer then kills Tim by stabbing him in his stomach. When Bub looks for Tim, the murderer grabs him and crushes his head under a box crusher. Later he kills Randy by impaling him on a meat hook. The murderer kills Dave by splitting his head with a meat cutter. The murderer dismembers his victims and leaves body parts around the store. ........
Source: Wikipedia