Three stories of how America's obsession with firearms impacts its citizens are explored in this independent drama. Carl Wilk (Donald Sutherland) runs a gun shop in Virginia that has been owned and operated by his family for generations. Carl sees the shop as his family's legacy without paying much mind to what happens with the weapons he sells. When his granddaughter Mary Ann (Linda Cardellini) needs money for college, Carl gives her a job in the store, and while she's hesitant at first, she becomes fascinated with the merchandise as time passes. On the West Side of Chicago, Carl Carter (Forest Whitaker) is the principal of a high school where violence has become a sad fact of life. As Carl and his wife, Sara (Garcelle Beauvais-Nilon), fear for their young son as they worry he could either fall prey to the violence of their community or embrace it himself, Carl receives a severe emotional blow when Jay (Arlen Escarpeta), one of his most promising students, is discovered carrying a pistol. And in Oregon, Janet (Marcia Gay Harden) is a single mother still troubled by the death of her teenaged son three years before, who took his own life after killing a handful of his classmates in a violent incident at a high school. As Janet deals with sharp words from the community, many of whom believe she should be held responsible for her late son's actions, she is unsure how to handle her surviving son, David (Christopher Marquette), who is now of high-school age. American Gun was the first feature film for writer and director Aric Avelino.