The mother of Michael Brown says she'll never forget the day a police officer killed her son in Ferguson.

Lezley McSpadden says she was taking a cigarette break from her grocery store job in Clayton, another St. Louis suburb, when a friend called to say someone had been shot near Canfield Green Apartments.

Within minutes, her cellphone rang again. It was a family member declaring the victim was McSpadden's 18-year-old son. The shooter was a police officer.

The next moments grew more and more intense as McSpadden's co-worker drove her to the scene where she quickly spotted clothing that matched her son's.

McSpadden recounts what happened that day in August 2014 in her autobiography, "Tell the Truth & Shame the Devil," set for release Tuesday and co-written by Lyah Beth LeFlore.