It’s been almost 100 years since New York City’s government made protecting child welfare part of its job–a job now carried out by the Administration for Children’s Services, or ACS, an agency which, with a 2010 budget of $2.6 billion and nearly 6,100 full-time staffers, carried out nearly 60,000 investigations of possible child abuse or neglect last year.

Most of ACS’s cases never make the papers. But sometimes high-profile cases do surface – Nixmary Brown, Marchella Brett-Pierce, and just last month, Kymell Oram, an 18-month-old boy born addicted to heroin and apparently beaten to death by his foster-mother’s teenaged boyfriend. With the media attention often comes calls for reform of the system–or, as in the recent indictment of two ACS workers in Brett-Pierce’s death, demand that individual decision-makers be held accountable.

Indeed, the world of child welfare is landscaped with a web of laws, regulations, legal precedents and government agencies, but as reporter Helen Zelon tells interviewed Don Mathieson below, the human factor is what determines whether system succeeds or fails.