On January 29, 2008, just days after a bitter winter storm, Nova Scotians watched with breaking hearts as a young mother in the small town of Bridgewater, Nova Scotia, pleaded on the supper-hour news for help finding her missing twelve-year-old daughter. For thirteen days, the country held its breath as the search for Karissa Boudreau continued. When, finally, frozen toes were found poking out of a snowbank, police confirmed Karissa was dead.

Shock quickly turned to anger when Karissa's mother, Penny Boudreau, was arrested for the murder of her only child. A year later, Penny sat in the prisoner's box in Nova Scotia Supreme Court. The moment seasoned journalist Sherri Aikenhead heard Penny confess to the killing, she knew she would write this story.

Aikenhead scoured official Bridgewater Police records, RCMP investigative records, court records, and Penny Boudreau's Parole Board of Canada decisions to recreate what happened fifteen years ago. Through interviews with Karissa's circle of family and friends, and including a first-hand account from a key undercover agent who reveals how the Mr. Big operation extracted Penny's confession, Aikenhead skillfully builds a powerful and intimate narrative of what really happened to "Bridgewater's daughter." With fifteen black-and-white photos, some provided by Karissa"s family members, Mommy Don"t takes readers on a heart-pounding journey into the unfathomable question: how could a mother murder her own daughter?