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Marc Craig Gann

About me

Marc Gann is one of the most highly regarded lawyers on Long Island. An AV-rated attorney who served as a past president of the 6,000-member Nassau County Bar Association from 2010-2011, Gann is on the "short list" of preeminent Nassau County criminal defense practitioners, and has handled numerous high-profile cases throughout the NY metropolitan area. 


Mr. Gann also serves on the Grievance Committee for the Tenth Judicial District (reviewing the legal competence and professional conduct of lawyers in the Tenth Judicial District). He is listed in the Bar Register of Preeminent Lawyers, and in 2014 was named to the list of New York Metro Super Lawyers.


An experienced trial lawyer, Mr. Gann defends all types of criminal cases - from minor traffic matters and drunk driving cases to the most serious major felonies - in the courts of Manhattan, Brooklyn, Queens, the Bronx, Staten Island, Nassau County and Suffolk County. He has handled serious felony charges in both the Southern and Eastern Federal Districts of New York and is particularly experienced in the defense of murder cases, and was certified to handle death penalty cases by the New York Capital Defender's Office. He has handled numerous homicide cases including a double murder in Nassau County, and has been lead counsel in the defense of a multi-defendant murder and kidnapping case that received national attention. He is also experienced in the defense of drug cases, including cases involving anabolic steroids and other performance enhancing drugs.


Mr. Gann has taken verdicts on major felony charges such as burglary, robbery, drug sale and commercial fraud. He has examined and cross-examined all types of witnesses from civilian and police witnesses to experts in areas such as ballistics, fingerprints, serology and forensic pathology. He also has expertise in the defense of Driving While Intoxicated cases, having defended many hundreds of these cases. Having prosecuted drunk driving cases exclusively for a portion of his tenure as an assistant district attorney, trying numerous cases to verdict, he has a substantial practical advantage in now defending these cases.


Prior to his role as President of the Nassau County Bar Association, Mr. Gann also previously served as an elected Director of the NCBA.  He is Past Chair of the Criminal Courts Law and Procedure Committee of the Bar, where he planned and chaired continuing legal education programs and seminars for criminal lawyers throughout the county. He was honored as the recipient of the Association's 2001 Directors' Award for his outstanding contributions the legal community.


He has frequently lectured to the local and State Bar Associations and the National Institute of Trial Advocacy. In recognition of his superlative trial skills, he was asked to serve as Team Leader for the 2002 National Institute of Trial Advocacy program at Hofstra University Law School. Mr. Gann continues to serve as Adjunct Faculty at Hofstra Law.


He has been interviewed by the media on many occasions regarding issues of criminal law, and he often appears on local television. He is a past president of the Former Assistant District Attorneys Association of Nassau County and is a member of the American Bar Association and other legal and professional associations. He is also highly active in community associations and volunteer programs, including serving for many years in a Bar association student mentor program at a local middle school.


Following his tenure as a prosecutor in Nassau County, Mr. Gann spent several years in Baltimore handling both criminal and civil matters in State and Federal court before returning to New York to form Collins, McDonald and Gann, P.C.



Practice areas


  1. Criminal Defense: 60%
    31 years
  2. White Collar Crime: 10%
  3. Violent Crime: 10%
  4. Federal Crime: 10%
  5. DUI & DWI: 10%
    31 years



Free consultation (60 minutes)

Payment types:

Cash, Check, Credit card

Attorney endorsements

10 total 

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  • Gerard Charles McCloskey

    I have had the pleasure of working with Marc on several criminal matters in Nassau County. Marc is one of the most well respected and knowledgeable criminal defense attorneys on Long Island. I highly recommend Marc for any criminal defense case.


    Gerard McCloskey Criminal Defense Attorney
    Relationship: Fellow lawyer in community

  • David Joseph Barry

    When it comes to criminal defense, Marc Gann is second to none. I have known Marc for over seven years, and his demonstrated trial skills and reputation in the legal community allow him to consistently deliver results for his clients. I endorse highly endorse Marc for any criminal defense issue.


    David Barry Criminal Defense Attorney
    Relationship: Fellow lawyer in community

Contact info

138 Mineola Boulevard
Mineola, NY, 11501


NYCurrently registered 198503/13/2015
We have not found any instances of professional misconduct for this lawyer.
Avvo contributions
Legal answers
Award nameGrantorDate granted
AV Preeminent 5.0 out of 5 Peer Review RatedMartindale-Hubbell2015
Directors' AwardNassau County Bar Association2001
Work experience
TitleCompany nameDuration
PartnerCollins, McDonald & Gann, P.C.1990 - Present
Association namePosition nameDuration
Nassau County Bar AssociationPresident-Elect2009 - Present
School nameMajorDegreeGraduated
Hofstra University School of LawLawJD - Juris Doctor1984
Franklin and Marshall CollegeGovernmentN/A1981