Eyewitness (1981)

Manhattan janitor Daryll Deever is fixated on hard-charging TV commentator, Tony Sokolow; he tapes her commentary daily to watch after work. When a wealthy Vietnamese man, with many shady connections, is murdered in the office building where Daryll works, Tony shows up to cover the story and Daryll introduce himself. She thinks he may know something, so she pursues him; he pretends he might to keep her interested. This romantic cat and mouse game goes on under the watchful eyes of the killers, who think that Daryll and Tony do know something. The killers start their own game of cat and mouse.