Debra Winger was given the choice of the two roles in La veuve noire (1987); she chose the role of the FBI agent, because she didn't understand the motivation as to why the Black Widow kills, so the title role went to Theresa Russell.
According to "The '80s Movie Rewind" website there is an alternate ending to the film. "Theresa Russell goes to jail, Debra Winger walks out of the building, that's all. The other times . . . it has ended with . . . Debra Winger sitting on a tropical beach having a drink, wearing a big sunhat...".
Many movie posters for the film featured a long text preamble that read: "Every man she marries is mysteriously murdered. One woman has uncovered the truth. But proving it could be fatal". This thriller film noir actually debuted around six months prior to the same 1987 year's big box-office suspenser hit Liaison fatale (1987).