Trenchcoat in Paradise (1989)

Eddie Mazda is a hard nosed private eye who gets in too close to the mob and is forced to leave Jersey City. He decides to open up shop in Hawaii. In no time, he finds a business, a partner, and lands the biggest case on the island: the murder of a land developer. With every step he takes getting close to the murder, he learns more about how the rich betray each other and how personal the murder is.