Ten years after her documentary À double tour Marie Cadieux revisits the circumstances of Diane Charron, an inmate profiled in the earlier film. Will Diane Charron ever be free? She began a life sentence behind bars in 1981 when she was entangled in a friend's act of revenge and ended up stabbing a stranger to death. She had just turned 19. We follow the story of Diane's life, from her own testimony and that of corrections officers, prison case-workers and psychiatrists. Sentenced to life asks serious questions about prisoners with mental health problems.