Irwin brings over a half century of legal knowledge and experience with personal injury, products liability, malpractice, labor, criminal, insurance, and disciplinary law cases to Sonneborn, Spring & O'Sullivan, P.C. 

Prior to joining the firm, he operated his own civil litigation firm in Syracuse for many years and earlier worked in civil and criminal law in New York City. He has lectured on trial practice for a variety of legal associations and hospital medical staff, served as an adjunct professor with the Syracuse University College of Law, and been an assistant district attorney for Onondaga County.  In addition to winning numerous cases, he has also written articles for legal and medical publications and been a pioneer in the development of many litigation procedures.

Over the years, Birnbaum has participated in numerous organizations, including the Legal Aid Society; National Board of Trial Advocacy; Onondaga County, New York State and American bar associations; New York State Trial Lawyers Association; and Association of Trial lawyers of America.  He helped promote ethical legal practice as the chairman for the Roscoe Pound Foundation Commission on Professional Responsibility, and co-founded the National Board of Trial Advocacy and the Onondaga Neighborhood Legal Services Corp.  Birnbaum has served on the board of directors for several local organizations, including the Dunbar Association, Planned Parenthood and Enable.