Ann Miller still grieves deeply five months after her son and only child was killed during the Virginia Tech mass shooting. A lifelong gun rights advocate, she works passionately as an executive for a gun rights organization, the American Rifle Society.
One morning, Miller opens an anonymous package containing an AK-47 assault rifle sent to her ARS department. Entering an executive boardroom to deliver the assault weapon to her boss during a departmental meeting, two handgun shots ring out and she sprays 50 bullets in a matter of seconds killing 13 of her colleagues.
Two FBI agents with vastly different personalities and investigative approaches lead the ultra-high-profile investigation to determine if the mass shooting was a horrible accident as Miller contends or a brilliantly planned and executed mass murder to bring worldwide attention to the destructive capability of automatic and semi-automatic weapons like killed her son. As the FBI's investigation fails to uncover evidence that Miller pre-planned the shooting, the ARS spins the mass shooting events to characterize Miller as a mentally ill woman hellbent on avenging her son's death.
Having killed everyone in the boardroom, Miller stands trial for 13 first-degree murders as both the perpetrator and only witness. A surprise piece of evidence surfaces at the end of the trial which renders a verdict but still leaves questions unanswered.