Predator 2 (1990)

Lt. Harrigan (Danny Glover) is a cop fighting the good war against drugs. But recently, the major drug lords have been killed off in a very brutal fashion. His superiors tell him to stay out of it, but Harrigan knows that something is wrong. His instincts are right when he discovers that the person behind the murders is none other than the Predator, the human-hunting alien who likes to make trophies out of his victims' skulls. But how can Harrigan stop the Predator when it can turn invisible and kill him without him knowing it?