Black Widow

Federal agent Alexandra Barnes (Debra Winger) believes that Catherine Petersen (Theresa Russell) is a serial killer who marries rich men and then murders them for their money. But since Catherine is seemingly a master of disguise and has multiple identities, Alexandra can't prove anything with conventional detective work. With no other option, she goes undercover, pursuing the same man (Sami Frey) as Catherine, and hoping that Catherine will slip up and reveal her true identity.