Dark Obsession (1989)

Hugo (Gabriel Byrne), heir to a fortune, is married to Ginny (Amanda Donahoe). They have a young son, and she seems devoted to Hugo, but jealousy wracks him. He imagines her in the arms of a colleague, he spies on her, he rages. One night, after drinking with members of his regiment, he runs his car over a woman: she dies, and all but one of his pals urge him to drive on. Why didn't he stop or swerve? She looked like Ginny. A psychological tug of war ensues: Peter (Struan Rodger), Hugo's business associate, wants to use the cover-up to leverage power over the estate; Jamie (Douglas Hodge), who's dating Hugo's sister, wants to go to the Police. Hugo's family closes ranks. As the Police investigation closes in, who wins the power struggle?