William S. Petrillo
Admitted to Practice:
  • New York
  • The City University of New York School of Law at Queens College, J.D.
  • St. John’s University, B.A.
  • Cross Examination: Marino Institute, 2016
  • Coutroom Testimony: Nassau Country Police Academy, 2016
  • Jury Selection: Hofstra Law School, 2016
  • more...

William S. Petrillo

Founding Partner
Download vcard here: William S. Petrillo
1103 Stewart Avenue | Suite 200
Garden City, NY 11530
Phone: 516.678.2800
Email: william@saponepetrillo.com

William S. Petrillo, a member of the New York Bar since 1995, limits his practice exclusively to defending criminal cases. He defends clients in state and federal Court, ranging from the most serious and complex crimes to minor offenses. He has procured acquittals in many difficult cases, including high profile trials. Many of Mr. Petrillo's cases have been publicized by every major television network and newspaper, including many that received national and international recognition. He is often quoted and interviewed as a legal expert for these media outlets as well.

After graduating from St. John's University, Mr. Petrillo joined the New York City Police Department where he gained valuable life experience as a police officer for six years. He then left the police department to attend the City University of New York School of Law at Queens College. In law school, Mr. Petrillo was chosen to be a member of the trial advocacy team which represented the school in a national competition in Chicago, consisting of 25 law schools. Judged by lawyers and judges from around the country, Mr. Petrillo received the highest rating of all participants.

Upon graduating from law school in 1994, Mr. Petrillo became an assistant district attorney at the Nassau County District Attorney's Office where his career in litigation began. He immediately distinguished himself as a trial attorney and was quickly promoted to the felony trial bureau. Here he was assigned a wide variety of very serious cases and acquired extensive and successful trial experience.

After obtaining invaluable courtroom experience, Mr. Petrillo entered private practice in 1998 when he joined a criminal defense firm. Here, he continued on his path as an active trial lawyer and established himself as the firm's in house trial counsel. For the next four years Mr. Petrillo continually and successfully tried a wide range of cases in multiple jurisdictions ranging from the most serious and complex cases to minor cases. In 2002, Mr. Petrillo founded The Law Offices of William S. Petrillo, P.C. He continues to regularly try cases and concentrates exclusively in all aspects of criminal defense in state and federal court.

Mr. Petrillo is often referred cases that are trial ready from other attorneys. He is routinely consulted by members of the legal community to advise on trial issues and issues of criminal law, and has been retained by law firms as a consultant to assist their attorneys. Mr. Petrillo is a sought after frequent lecturer who has taught large groups of lawyers, law students, District Attorneys and law enforcement entities on many occasions.

Mr. Petrillo is listed in The National Trial Lawyers Top 100 Criminal Defense Trial Lawyers and is a member of The Criminal Courts Bar Association of Nassau County, The Nassau County Bar Association and The Former Assistant District Attorney's Association of Nassau County. He is a former member of the National Association of Distinguished Counsel, The National Association of Criminal Defense Attorneys, The New York State Association of Criminal Defense Attorneys and The New York State Trial Lawyers Association.