A Mississippi police chief is calling it the “worst case of child abuse that I have ever seen.” A 4-year-old girl was fatally beaten, a 3-year-old is a critical condition, and their mother and her boyfriend are under arrest. Police in Natchez said James Christopher Anderson, 24, assaulted both children, then forced them to walk a quarter of a mile to his mother’s apartment before emergency services were called, the Clarion Ledger reported. The girls’ mother Lakeisha Marie Jones, 25, allegedly knew they were being abused—and the state child-welfare agency reportedly had investigated the family in the past.