Cobra is a 1986 action film directed by George P Cosmatos and starring Sylvester Stallone, Reni Santoni, Brigitte Nielsen, and Andrew Robinson.

Marion Cobretti, codenamed ‘Cobra’ (Stallone) is a police officer from a division of the Los Angeles Police Department known as the ‘Zombie Squad’. He is called into a hostage situation at a grocery store when negotiations fail. Cobretti kills the gunman, but before his death the criminal mumbles of a New Order: a group of supremacists who believe in killing the weak and leaving only the strongest and themselves to live and rule the world.

As the bodies are removed from the supermarket, Cobretti is admonished by Detective Monte (Andrew Robinson) for his seeming disregard for police procedures and protocols. After witnessing several individuals, including the Night Slasher (Thompson), who is the Order’s leader at the scene of one of the murders late at night, Ingrid Knudsen (Nielsen) a model, becomes the target of the group because she was the only living witness to their crimes. After one attempt on her life, she is placed under the protective custody of Cobretti and his partner, Sergeant Gonzales (Santoni). The LAPD decides it will be safest if they relocate from the city.

Cobretti becomes romantically involved with Ingrid shortly after venturing out into the countryside, but one of the Order’s leaders (who is a police officer traveling alongside the Cobretti party) reveals the location of their whereabouts; despite Cobretti’s suspicions and mistrust of the officer, he does nothing and stays the night in a motel. The Order moves in at dawn and besieges the small town in which they are staying. With barely enough time to react, the attackers storm the motel room Cobretti is in with Ingrid, wounding Gonzales in the process. After eliminating every member except for the Night Slasher, Cobretti and the leader ultimately engage in a deadly hand-to-hand duel inside the steel mill.

Summary via Wikipedia.