Sean co-founded the Firm in 2015 and is the Chair of the Firm’s Executive Committee.
Described by Chambers USA as “excellent, thoughtful, and dedicated,” and “an incredibly calm voice of reason,” he is equally adept fighting for his clients in the courtroom before judges and juries, conducting investigations involving dozens of witnesses, and working closely with his clients behind the scenes to help navigate their most difficult challenges.
He has had some of his most pronounced success in persuading prosecutors and regulators to decline to even bring criminal cases and enforcement actions, often after years of investigation, and in convincing judges to dismiss meritless complaints and lawsuits.
“Sean is one of the best, if not the best, lawyers I have had the pleasure to work with. I hope to not have to call a lawyer again. But if I need to, he will be my first phone call.” Chambers USA Commentator
The desire to have the freedom and flexibility to provide personal service to each of his clients led Sean to help found the Firm; it now handles litigation, regulatory, investigatory and monitorship related services of considerable size and complexity.
“I would absolutely recommend Sean Haran to anyone in need. He is a master of his craft.” Chambers USA Commentator
Sean takes criminal and civil cases to trial before juries and judges in federal and state courts, as well as in federal administrative proceedings and before arbitration tribunals. And he has defended scores of senior executives, professionals, and companies in their capacity as subjects, targets and witnesses in connection with federal, state and local criminal and regulatory investigations and proceedings.
“Sean Haran is one of the most professional and intelligent lawyers and human beings I ever worked with.” Chambers USA Commentator
As an Assistant U.S. Attorney in the Eastern District of New York (EDNY), he took more than a dozen cases to jury verdict and supervised federal prosecutors in the Business and Securities Fraud Section. While an AUSA, Sean handled many of the highest profile and complex white collar criminal matters in the Office, including prosecutions and grand jury investigations of securities fraud, health care fraud, bank fraud, money laundering offenses, bribery, tax fraud, obstruction of justice, racketeering, material support of terrorism and import/export control violations.
“Sean is very effective in terms of diffusing situations and getting great results for clients.” Chambers USA Commentator
Show More +A strategic thinker with a calming presence in the midst of crisis situations and able to put his clients at ease. He ‘distills complex matters to their essence’ and ‘knows his way around a courtroom incredibly well.’
– Chambers USA
Experience
Secured a trial verdict and a holding that there was insufficient proof of client’s fraudulent intent and therefore that millions of dollars in debts should be discharged, notwithstanding the client’s prior guilty plea in federal court and notwithstanding a prior state court ruling holding that the client had breached his fiduciary duties.
Represents a worldwide technology and digital media company in litigation and at an upcoming jury trial concerning the Company’s air rights and development rights in its landmark brick and mortar New York City Headquarters. The Georgetown Company v. IAC, Dkt. No. 651304/2016 (Sup. Ct., N.Y County, Commercial Division)
Represents a leading global investment bank and financial services company along with numerous of its executives, investment bankers and financial advisors in various ongoing capacities, including in connection with federal criminal investigations, regulatory investigations and proceedings and internal investigations.
Represents and represented a leading cryptocurrency platform and various of its executives in multiple matters, including in connection with federal grand jury investigations, CFTC, SEC and NYAG investigations, and litigation in federal court brought under the securities fraud statutes.
Represents a national food services company in ongoing civil and commercial litigation in various federal and state courts.
Represents a national real estate development company in various federal and state court litigations, including in class action antitrust litigation.
Represents a global online travel company in ongoing litigation in federal and state courts, throughout the country, including in connection with state and local tax issues and federal claims brought under the Helms-Burton Act.
Represents a construction services company and its executives in connection with federal criminal antitrust proceedings and related class action litigation.
Represented an international sports marketing company and its chief executive in complex litigation; Sean persuaded a New York state judge to dismiss a civil suit against his client notwithstanding the client’s prior guilty plea in federal court. Confederacion Sudamericana De Futbol v. International Soccer Marketing, Inc., Dkt. No. 655619/2016 (Sup. Ct. N.Y. Co, Commercial Division).
Together with WMHW partner John Curran, led the monitorship of one of the world’s largest banks, and supervised an extensive “look back” transaction review and compliance assessment of the bank’s New York branch in connection with state and federal banking consent decrees.
Represented former Kings County District Attorney Charles “Joe” Hynes in an extensive federal criminal investigation; prosecutors closed the lengthy investigation without bringing charges.
Represented the former General Counsel of the Port Authority of New York and New Jersey in lengthy parallel SEC and state grand jury investigations into allegations of federal securities fraud and violations of New York’s Martin Act; no charges filed.
Represented a law firm partner in an SEC investigation into fraud in municipal bond offerings; no charges filed after multiple threats of enforcement proceedings.
Represented a well-known real estate developer in a highly publicized and multiyear federal criminal investigation into political corruption and “theft of honest services” fraud; no charges filed.
Represented a household name internet company in a consumer protection investigation by the Office of the New York Attorney General; no charges filed.
Recognitions
Ranked in Litigation: White-Collar Crime & Government Investigations — New York, Chambers and Partners USA (2020-2025)
500 Leading Litigators in America, Lawdragon (2024)
500 Leading Lawyers in America, Lawdragon (2024)
National Practice Area Star and Local Litigation Star, General Commercial Litigation and White Collar Crime, Benchmark Litigation (2018 -2025)
Best Lawyer, Criminal Defense: White-Collar, U.S. News-Best Lawyers in America (2015-2025) [see selection methodology here]
Irish Legal 100