On the night of March 6, 2021, Maurine Mirembe left her 3-year-old daughter Bernice in the care of her friend, Zahra who had a little girl the same age. The next morning, just after Zahra fed the children breakfast, Bernice became severely ill and went into cardiac arrest.  As doctors worked to save her, Zahra arrived at the hospital – her own daughter showing the same symptoms. What no one knew was that the children had been poisoned. In 'He's So Evil', Crime Specialist Catherine McDonald recounts the story about of an obsession so deep it led to the death of an innocent child.