Mancuso has served as an assistant district attorney for nearly 27 years. He currently works in the Government and Consumer Frauds Bureau, investigating and prosecuting a variety of white-collar crimes and fraud schemes. Before that, he was assigned to the Public Corruption Bureau, where he prosecuted crimes committed by government officials and public employees.

Mancuso has been the deputy chief of the Commercial Frauds Bureau and chief of the Environmental Protection Unit at times during his tenure.

His legal career also included eight years in private practice, and he is admitted to practice in several federal jurisdictions.

Locally, Mancuso has been involved with volunteer organizations. He is now completing his term as president of the Kiwanis International Foundation. Mancuso has also been president of the East Meadow Chamber of Commerce and of the MIT Club of Long Island.

Mancuso is an alumnus of the Massachusetts Institute of Technology and Cornell Law School. His wife, Karen, is also a Cornell Law School graduate and a member of the Nassau County Bar Association. They are active parishioners at St. Raphael’s Church in East Meadow. Their adult children, Stephen and Cathy, are both engineers.