The GuardianMother admits killing her three childrenAFPLONDON — An American woman admitted to a court on Monday that she stabbed her three children to death in their Edinburgh home last year. California-born Theresa Riggi, 47, pled guilty to a charge of culpable homicide on the grounds of diminished ...Mother pleads guilty to killing her three childrenThe GuardianVIDEO: 'They live in our hearts and minds forever'BBC NewsU.S.