Introduction
Timothy D. Sini is a member of the Litigation Department, the Government Investigations & White Collar Defense practice group, and the Congressional Investigations and Crisis Management Teams.
My focus
With more than 18 years of experience in government investigations, crisis management, and litigation, I focus my practice on the following areas:
Internal and External Investigations
I handle a diverse array of matters involving government investigations or charges, including by agencies such as the Department of Justice, the United States Congress, state attorneys general, district attorneys, and regulatory agencies. I also conduct internal investigations for companies and nonprofits, as well as external investigations for clients, with the objective of uncovering theft, public corruption, and fraud negatively impacting their businesses.
As a former federal prosecutor in the Southern District of New York and as the former Suffolk County District Attorney where I led one of the largest prosecutors’ offices in the nation, I have personally handled and supervised hundreds of complex investigations and prosecutions involving a wide range of crimes, including RICO, public corruption, environmental crime, fraud, financial crimes, organized crime, labor offenses, among other offenses. My investigative and litigation experience include matters that are multi-jurisdictional and international in scope.
As the former Police Commissioner of the Suffolk County Police Department and as the former Suffolk County District Attorney, I led internal investigations into each agency rocked by high-profile scandals and successfully developed and implemented corrective action plans.
With these unique experiences, I am able to protect my clients’ interests by conducting comprehensive investigations, proactively identifying risks, and developing plans to ensure compliance and minimize future vulnerabilities.
Criminal Defense & Litigation
I use my skills and experience as a former federal prosecutor in the Southern District of New York and the District Attorney of one of the largest prosecutor’s offices in the nation to effectively represent individuals and entities in connection with government investigations, criminal prosecutions, and civil litigation. I’ve personally handled numerous jury trials, appeals, and other contested court proceedings. My experience includes trying federal felony cases to verdict, involving novel, complex factual and/or legal issues. As District Attorney, I supervised and strategized hundreds of successful investigations and prosecutions. I leverage this experience to help corporate and individual clients involved in civil and criminal litigation.
Crisis Management
I am no stranger to crisis. I took over both the Suffolk County District Attorney’s Office and the Suffolk County Police Department in crisis: both agencies were led by individuals who have since been convicted of federal corruption offenses and were using their respective organizations in furtherance of their criminal schemes. As both Police Commissioner and District Attorney, I led massive internal investigations and instituted comprehensive corrective action measures, which restored the integrity and efficacy of both agencies. I also led the Suffolk County District Attorney’s Office during the worst of the COVID-19 pandemic and the most sweeping change in criminal law in a generation. My proven success in crisis management allows me to swiftly and strategically advise and counsel individuals and entities facing all forms of emergent situations, including criminal, civil, regulatory, and/or reputational in nature.
Compliance
I assist clients in developing and implementing policies and protocols to ensure compliance with applicable law and regulations and to minimize future risk. I have advised clients in the areas of corporate governance, the pharmaceutical industry, healthcare, lobbying and government consulting, government procurement, private investigations and security, physical security, etc. My broad experience in complex investigations and prosecutions coupled with my in-the-trenches reform work positions me well to handle compliance for clients in a broad array of areas.
Representative experience
Tim brings to his clients a truly unique blend of experience in investigations, litigation, and crisis management. He previously served as an Assistant United States Attorney in the Criminal Division of the U.S. Attorney’s Office for the Southern District of New York under U.S. Attorney Preet Bharara; the District Attorney for the Suffolk County (Long Island) District Attorney’s Office, one of the top 20 largest prosecutors’ offices in the nation; and the Police Commissioner of the Suffolk County Police Department, the 11th largest police department in the nation. Tim has been recognized as an expert in investigations and prosecutions, testifying before the President’s Commission on Law Enforcement & the Administration of Justice; the U.S. House of Representatives, Subcommittee on Counterterrorism and Intelligence; and the U.S. Senate, Committee on the Department of Homeland Security and Government Affairs. Tim also served on the White House’s Office of National Drug Control Policy, NY/NJ Regional High Intensity Drug Trafficking Area (HIDTA) Team where he worked with law enforcement, diversion investigators, and regulators to enhance compliance with the Controlled Substances Act and reduce drug overdoses in the region. He uses his past experience to represent a diverse client base, including entities, individuals, and executives, in all types of investigations, litigations, prosecutions, and crisis management situations.
- Represent a senior intelligence official in connection with a Congressional investigation and hearing
- Represent and defend high-profile individuals and companies of all sizes in connection with government investigations and prosecutions, including matters involving public corruption and securities, healthcare, and financial fraud
- Represent victims and witnesses before government agencies
- Counsel pharmaceutical and healthcare clients in connection with the Controlled Substances Act and other applicable regulations
- Counsel corporate clients in crisis, including physical security breaches and cyber intrusions
- Conduct internal investigations for corporate clients, including in the area of corporate theft, corporate governance, and employee misconduct allegations
- Conduct external investigations for clients, including in the area of public corruption and corporate fraud
- Represent and defend a medical doctor charged federally with healthcare fraud in connection with the provision of COVID-19–related services
- Represent a medical practice in connection with a New York State Attorney General investigation regarding medical billing
- Represent founder and former CEO of a security technology company in connection with a private equity dispute
- Represent cannabis companies in litigation and in connection with regulatory compliance
- Draft policies for companies, including large multinational companies, and counsel them regarding physical security and workplace threats
- Counsel lobbyists, consultants, and former public officials in connection with applicable regulations and ethics rules
- Counsel FFLs regarding compliance with local, state, and federal firearms laws
- Serve as outside pro bono general counsel for Long Island Council on Alcoholism and Drug Dependency, a regional not-for-profit organization dedicated to helping those suffering from addiction
Prior Experience
- Suffolk County District Attorney’s Office, Suffolk County District Attorney, January 2018–December 2021
- Suffolk County Police Department, Police Commissioner, November 2015– December 2017
- Suffolk County Assistant Deputy County Executive for Public Safety, August 2014–November 2015
- United States Attorney’s Office, Southern District of New York, Assistant United States Attorney, March 2010–August 2014
- Prior to government service, Tim clerked for a United States District Judge for the Southern District of New York and a United States Circuit Judge for the Second Circuit Court of Appeals. He also worked as a commercial litigation associate at a large international law firm and a litigation boutique
Clerkships
- United States Court of Appeals for the Second Circuit, Law Clerk for the Honorable Chester J. Straub, August 2008–March 2010
- United States District Court for the Southern District of New York, Law Clerk for the Honorable William C. Conner, October 2006–September 2007
Looking ahead
Expect increased enforcement by government at all levels in white-collar matters, with a focus on ensuring that companies implement robust compliance programs and respond appropriately to corporate wrongdoing. Continue to expect sophisticated bad actors to take advantage of cyber vulnerabilities, requiring companies to be proactive in their defenses and responses to such threats. Also, keep an eye on the cannabis market and the varying regulatory schemes with the federal government likely to reschedule marijuana in the next several months.
In the news
- Bloomberg Law
The targeting of CEOs prompts organizations to evaluate safety
Feb 26, 2025Government Investigations & White-Collar Defense partner Tim Sini and Complex Disputes associate Ryan Maloney, both of the Long Island office, contributed this article discussing the need for organizations to have strong executive protection policies in place. Tim and Ryan also discuss the unique set of legal requirements that vary by jurisdiction in connection with protecting an organization’s executives.
- Long Island Business News
AI in corporate compliance: Is your organization ready for a DOJ assessment?
Dec 19, 2024Government Investigations & White-Collar Defense partner Tim Sini and Complex Disputes associate Ryan Maloney, both of the Long Island office, contributed this article, discussing how businesses should reexamine compliance efforts based on updated DOJ guidance. The agency recently announced that when evaluating a company’s compliance program, it will now review how the business assesses and manages risks associated with its use of technology—including artificial intelligence.
- Bloomberg Law
Tesla lawyers get top legal roles elsewhere
July 19, 2024This article highlighting David Misler’s new role as general counsel and corporate secretary for BusPatrol America LLC mentions NP for representing the company, which uses artificial intelligence technology to enhance stop-arm safety cameras on school buses. Long Island Government Investigations & White-Collar Defense partner Tim Sini represents BusPatrol.
- Law360
Fire Island superintendent runs it as ‘his fiefdom,’ suit says
Aug 23, 2023This article, which covers a complaint filed by a Fire Island resident against Fire Island National Seashore superintendent Alexcy Romero, mentions GIWC partner Tim Sini and Construction & Real Estate Litigation associate Neil Diskin, both of Long Island, for representing the plaintiff in the case.
- Newsday
Summer Jam still on, despite Nassau attempt to ban outdoor concert
June 2, 2023This article covering an annual hip-hop festival’s ability to proceed—after Nassau County, New York attempted to ban part of the event—quotes Long Island Government Investigations & White-Collar Defense partner Tim Sini, who is leading a team representing the festival organizers. In addition to Tim, the NP team includes Complex Disputes counsel Bryan Lewis and Construction & Real Estate Litigation associate Neil Diskin, both of the Long Island office.
- Long Island Business News
Newsmakers of the year
Dec 29, 2022This article highlighting prominent Long Island business news from 2022 includes the arrival of Long Island Government Investigations & White-Collar Defense partner Tim Sini to NP, noting his previous role as Suffolk County District Attorney.
- City & State New York
The 2022 Long Island Power 100
Nov 7, 2022Long Island Government Investigations & White-Collar Defense partner Tim Sini is featured in this article as one of the publication’s “2022 Long Island Power 100,” recognizing influential individuals shaping the island’s future. The article notes Tim’s tenure as Suffolk County District Attorney, highlighting his indictment of 96 MS-13 gang members and associates.
- Long Island Herald
Top lawyers honored during annual Heritage Club event
Sep 30, 2022This article mentions Long Island partner and Labor & Employment practice leader Tara Daub, Government Investigations & White-Collar Defense partner Tim Sini, and Affordable Housing & Real Estate partner Sami Groff, who were all named “Top Lawyers of Long Island” for 2022 by the publication’s parent company. NP was also one of four firms honored this year.
- amNY Metro
Schneps Media celebrates New Yorks Power Professionals
Long Island Government Investigations & White-Collar Defense partner Tim Sini is featured in this article as one of New York’s “Power Lawyers” honored by the publisher at an event last week. The article notes that Tim and his fellow honorees come from “diverse backgrounds and from diverse industries making for an incredible opportunity for developing new and meaningful connections.”May 19, 2022 - Newsday
Doctor charged with pandemic-related healthcare fraud
This article covers Long Island Government Investigations & White-Collar Defense partner Tim Sini’s successful bail argument on behalf of a prominent cardiologist accused of healthcare fraud. A federal judge granted the bail request and allowed the doctor to continue billing claims to Medicare and other federal healthcare programs while his case is pending. The NP team representing the doctor also includes Long Island Healthcare partner Michele Masucci and associate Michal Ovadia.April 20, 2022 - Long Island Business News
Power players
This article covering a trend of prominent Long Island attorneys joining BigLaw firms from public sector and in-house roles features Long Island Government Investigations & White-Collar Defense partner Tim Sini for his arrival to NP this year, quoting Tim on his reasons for joining the firm. The article also quotes Long Island office managing partner Allan Cohen on how Tim’s prior experience benefits NP.April 14, 2022 - Stateline (The Pew Charitable Trusts)
Thieves hit on a new scam: Synthetic identity fraud
This article on synthetic identity fraud, which combines real Social Security numbers with mismatched or phony names to create new identities, quotes Long Island Government Investigations & White-Collar Defense partner Tim Sini on how law enforcement agencies across states usually need to cooperate on related investigations. The article mentions Tim’s role in investigating a major scheme when he was Suffolk County (NY) District Attorney.April 7, 2022 - Crain’s New York Business
People on the move
This roundup of notable moves and hires highlights the recent arrival of Long Island Government Investigations & White-Collar Defense partner Tim Sini to the firm, noting details of his practice as well as his former roles as a federal prosecutor and as district attorney and police commissioner for Suffolk County, New York.Feb 14, 2022 - The National Law Journal
Prosecutor moves highlight brisk demand for white-collar work
This article, which covers the growing shift among former federal and state prosecutors to join private practice, includes the arrival of Long Island Government Investigations & White-Collar Defense partner Tim Sini to NP. The article features insight from both Tim and GIWC practice group leader Rob Fisher, of Boston, on the anticipated surge of enforcement activity that could be driving this trend, and the networking among former prosecutors that often helps guide them to top law firms.Feb 2, 2022 - Innovate LI
As LI's legal landscape shifts, Nixon Peabody adds Sini
The following article comprise additional news coverage on Long Island Government Investigations & White-Collar Defense partner Timothy Sini and his arrival to the firm. Tim discusses his past experience as an assistant United States attorney, district attorney, and police commissioner, as well as his points of focus at the firm and NP’s growing GIWC group. Long Island office managing partner Allan Cohen, of the Healthcare group, is quoted on the unique and diverse experience that Tim brings to NP.Feb 1, 2022 - Long Island Business News
Sini joins Nixon Peabody
The following article comprise additional news coverage on Long Island Government Investigations & White-Collar Defense partner Timothy Sini and his arrival to the firm. Tim discusses his past experience as an assistant United States attorney, district attorney, and police commissioner, as well as his points of focus at the firm and NP’s growing GIWC group. Long Island office managing partner Allan Cohen, of the Healthcare group, is quoted on the unique and diverse experience that Tim brings to NP.Feb 1, 2022 - Law360
Nixon Peabody adds ex-Long Island DA to white collar team
The following article comprise additional news coverage on Long Island Government Investigations & White-Collar Defense partner Timothy Sini and his arrival to the firm. Tim discusses his past experience as an assistant United States attorney, district attorney, and police commissioner, as well as his points of focus at the firm and NP’s growing GIWC group. Long Island office managing partner Allan Cohen, of the Healthcare group, is quoted on the unique and diverse experience that Tim brings to NP.Feb 1, 2022 - WRCN-FM
Long Island News Radio
The following news coverage features the arrival of Long Island Government Investigations & White-Collar Defense partner Timothy Sini. Tim discusses his background as a former assistant United States attorney, district attorney, and police commissioner, as well as his enthusiasm to maintain his local roots amid NP’s international reach. Long Island office managing partner Allan Cohen, of the Healthcare group, is quoted on Tim’s impressive experience and the strengths he brings to the firm.Feb 1, 2022 - Newsday
Ex-Suffolk County DA Tim Sini joins big law firm
The following news coverage features the arrival of Long Island Government Investigations & White-Collar Defense partner Timothy Sini. Tim discusses his background as a former assistant United States attorney, district attorney, and police commissioner, as well as his enthusiasm to maintain his local roots amid NP’s international reach. Long Island office managing partner Allan Cohen, of the Healthcare group, is quoted on Tim’s impressive experience and the strengths he brings to the firm.Jan 31, 2022
Admitted to practice
New York
Education
Brooklyn Law School, J.D., magna cum laude
American University, B.A., magna cum laude
Federal Bureau of Investigation National Executive Institute Certificate in Executive Leadership, Law Enforcement (2017)
Harvard University, John F. Kennedy School of Government, Decisionmaking Certificate, Executive Education (2017)
Professional activities
- Boy Scouts of America, Suffolk County Council, Board of Directors
- Family & Children's Association, Board of Trustees
- White House’s Office of National Drug Control Policy, New York/New Jersey Regional High Intensity Drug Trafficking Area (HIDTA) Team, Former board member
- Touro Law Center & St. Joseph’s College, Former adjunct professor
Recognition
- 2022 Schneps Media Power Lawyer Award
- 2022 Top Lawyers of Long Island, by Richner LIVE and Herald Community Media
- 2021 Leadership Award, Long Island Federation of Labor
- 2019 Public Service Award, the Suffolk County Dr. Martin Luther King, Jr. Commission
- 2016-2021 Long Island Press Power List
- 2016 Person of the Year, ASIS International
Insights And Happenings
View AllProfessionals in the Practice Area
View AllRobert Fisher
Partner / Practice Group Leader, Government Investigations & White Collar Defense- Boston
- Office:+1 617.345.1335
- rfisher@nixonpeabody.com
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Hannah Bornstein
Partner / Deputy Practice Group Leader, Government Investigations & White Collar Defense- Boston
- Office:+1 617.345.1217
- hbornstein@nixonpeabody.com
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