Pretty Poison (1968) is a thriller film directed by Noel Black, starring Anthony Perkins and Tuesday Weld, about an ex-convict and high school cheerleader who commit a series of crimes.
While not generally considered an example of neo-noir, the film does include certain elements of the genre, including a femme fatale, a character trapped into circumstances beyond his control, criminal protagonists and, of course, murder.
The film was based on the novel She Let Him Continue by Stephen Geller; this was also the working title of the film.
There was a 1996 remake with the same title and plot.