Atlantic City-based Cooper Levenson—a go-to law firm on gambling issues within its home base and beyond—is expanding into the Big Apple with the rehire of a former firm partner.

Joseph C. Mahon, a trusts and estates lawyer, returned to assume the role of lead attorney for the firm’s New York City office, to be located at 45 Rockefeller Plaza.

Mahon was a partner at Cooper Levenson from 2001 to 2010, specializing in estate planning and wealth management. He left in 2010 for Frankfurt Kurnit Klein & Selz in New York, where he was a partner.

The New York expansion adds to the firm’s offices in New Jersey, Delaware, Florida and Nevada.