Skip to main content

About me

William S. Petrillo graduated from St. John's University with a Bachelor of Science in Criminal Justice.  He then joined the New York City Police Department where he worked for six years as a police officer.  Mr. Petrillo left the NYPD to attend law school at City University of New York School of Law at Queens College.  After graduating, he worked as an Assistant District Attorney at the Nassau County District Attorney's Office for four years where he gained voluminous trial experience.  He has been in private practice since 1998, specializing in criminal defense. He has represented a wide variety of clients in many different types of cases ranging from minor crimes to the most serious and complex offenses; both blue and white collar.  Mr. Petrillo has procured acquittals in many difficult cases, including high profile trials.  Many of his cases have been publicized by every major television network and newspaper, with several receiving national attention.  Mr. Petrillo is often referred cases from other attorneys that are trial ready, is routinely consulted by members of the legal community to advise on trial issues and has been retained by law firms as a consultant to assist their trial attorneys.


Photos and videos

928268 1414182817

Practice areas


  1. Criminal Defense: 100%



Retainer (always)

Payment types:

Cash, Check, Credit card

Attorney endorsements

4 total 

Are you an attorney? Endorse this lawyer

  • Lauren Riesenfeld

    I highly recommend Mr. Petrillo for anyone looking for a top notch criminal defense attorney. Mr. Petrillo is kind, intelligent and a skilled advocate. He goes above and beyond for his clients to ensure the best possible outcome for their case.


    Lauren Riesenfeld Criminal defense Attorney
    Relationship: Fellow lawyer in community

  • Oscar Michelen

    I endorse this lawyer. Bill is simply one of the best trial lawyers I have ever had the pleasure of knowing. Dedicated, thorough, an expert at cross-examination and a sharp legal mind. On top of that, he is personable and cares deeply about his clients. I wholeheartedly endorse him for anyone seeking a criminal defense lawyer.


    Oscar Michelen Commercial real estate Attorney
    Relationship: Worked together on matter

Contact info

William S. Petrillo, P.C.

1103 Stewart Avenue
Suite 200
Garden City, NY, 11530


NYCurrently registered 199507/11/2016
We have not found any instances of professional misconduct for this lawyer.
Avvo contributions
Legal answers
Award nameGrantorDate granted
Top 100 Criminal Defense Trial LawyersThe National Trial Lawyers2015
The Nation's Top One PercentNational Association of Distinguished Counsel2015
Work experience
TitleCompany nameDuration
PrincipalLaw Offices Of William Petrillo, P.C.2002 - Present
Of Counsel And In House Trial CounselCriminal Defense Firm1998 - 2002
Assistant District AttorneyNassau County District Attorney's Office1994 - 1998
Police OfficerNew York City Police Department1984 - 1990
Association namePosition nameDuration
The New York State Trial Lawyers AssociationMember2010 - Present
The New York State Association of Criminal Defense AttorneysMember2005 - Present
The National Association of Criminal Defense AttorneysMember2002 - Present
The Nassau County Bar AssociationMember2002 - Present
The Criminal Courts Bar Association of Nassau CountyMember1998 - Present
The Former Assistant District Attorney's Association of Nassau CountyMember1998 - Present
School nameMajorDegreeGraduated
City University of New York School of Law at Queens CollegeLawJD - Juris Doctor1994
St John's UniversityCriminal JusticeBS - Bachelor of Science1984
Speaking engagements
Conference nameTitleDate
Nassau County Police AcademyCourtroom Testimony2016
Nassau Academy of LawThe Fundamentals Of The Trial In A Criminal Case2016
Hofstra Law SchoolJury Selection2016
The Nassau Lawyers' AssociationCross Examination2015
Nassau Academy Of LawAnatomy of a Criminal Trial From Jury Selection to Summation, Practical Strategies & Suggestions2015
Marino Legal Institute - NYCThe Perfect Closing2015
Hofstra Law SchoolCorrecting The Injustice2015
The Nassau Lawyers' AssociationFrom Arrest To Arraignment2014
Nassau County Police AcademyCourtroom Testimony2014
Nassau Academy Of LawDefense Cross Examination & Summation2014
Hofstra Law SchoolFrom Jury Selection To Summation2014
Hofstra Law SchoolAttacking The Prosecution's Case2013
Hofstra Law SchoolWinning The Case Before The Trial2012
Hofstra Law SchoolThe Anatomy Of A Criminal Trial2011
City University Of New York School Of LawCross Examination2010
City University Of New York School Of LawClosing Argument2009
City University Of New York School Of LawProsecuting & Defending Fraud Cases2008
Nassau Academy Of LawDefense Cross Examination & Summation2007
Nassau County District Attorney's OfficeDefense Closing Argument2006
Nassau County District Attorney's OfficeOpening Statement & Closing Argument2005
Molloy CollegeTrial Preparation & Jury Selection2005
Nassau County District Attorney's OfficeDefense Closing Argument2004
Molloy CollegeAn Analysis Of A Murder Trial2003