This itself is not what's troubling, but she displays violent tendencies in her quite to start with appearance by stabbing Artie in the eye with a crayon.
In March 1980, soon after the medical doctor finally dumps Jean for a younger girl, a blend of amphetamine withdrawal and jealousy sends her into a rage, and she shoots him to loss of life in his possess household.
Its internal logic appears to be "search amazing initially, reveal why later", which also heavily contributes to the collection infamous Kudzu Plot.