Guardian Angel (1994)

Christine McKay is a cop. She and some other cops which includes her lover are pursuing some criminals. Her lover gets killed by a woman named Nina, who is later caught. Because of his death McKay leaves the force. A few months later a man named Hobbs calls McKay. When she goes to see him, he tells her he wants to hire her to protect him. It seems that Nina is his ex and he tells her she escaped. And Hobbs is worried she's coming for him. McKay goes to check it out and finds out it's true. She then goes back to Hobbs and finds Nina there but she doesn't do anything, instead she's looking for something but Hobbs claims not to know what she's talking about. So McKay stays to protect Hobbs and to get Nina.