Yesterday, Administration for Children's Services Commissioner John Mattingly turned in his resignation. While there have been numerous high-profile cases of children dying while their families were under ACS scrutiny, sources tell the Daily News that he was not pushed. Mayor Bloomberg said, "New York City has been extraordinarily lucky to have a nationally-renowned expert, John Mattingly, ably and tirelessly leading our Administration for Children's Services. When John came to us and said he wanted to return to his foundation work in Baltimore and have more time for his family, I asked him to reconsider."

Mattingly's tenure included the horrifying deaths of Nixzmary Brown, the child who died after her stepfather beat and tortured her—ultimately to death—while her mother did nothing to stop it, and the more recent death of Marchella Pierce, a four-year-old who was only 18 pounds. Pierce's death led the Brooklyn DA's office to charge two ACS workers with homicide. However, Mattingly did hire hundreds more case workers in an attempt to lessen workers' burdens.

Leaders of watchdog and advocacy groups were upset about Mattingly's departure. Children's Rights executive director Marcia Robinson Lowry said, "There are far too few child welfare commissioners anywhere in this country that share his courage, strength, integrity and tenacity. He aimed high and while he may not have hit every goal he set, his aim was dead on," while the Center for NYC Affairs' Andrew White said, "I honestly think this agency is so much more professional and the leadership is so much more focused on problem solving than a decade ago," and made note of the big budget cuts Mattingly's had to deal with, "It would take a toll on anybody to do that job. It's a brutal job." But the National Coalition for Child Protection Reform's director Richard Wexler said, "I think he was so personally affected by the horror-story cases that he lost sight of the fact that the majority of the cases are not horror cases."

Mattingly will return to the Annie E. Casey Foundation, which is a private child welfare charitable foundation. It's also believed his wife might have some medical issues.