,,, Mr. Lesser joined Thornton Law Firm as an associate in 1995 after previously clerking at the firm. He heads the firm’s Whistleblower litigation section, with a focus on representing individuals that report violations of securities laws subject to the SEC Whistleblowing statute and individuals that report fraud on the government through the Federal and state False Claims Act statutes.

In 2020 Mr. Lesser’s client, an FX trader who worked for Bank of New York Mellon, was awarded the then largest individual SEC whistleblower award in the history of SEC whistleblower litigation. The  client’s almost $50 million dollar award was for providing original information to the Securities and Exchange Commission that resulted in a successful enforcement action that returned a significant amount of money to harmed investors.

Mr. Lesser was rated as one of New England’s Top Rated Lawyers by ALM Media and Martindale-Hubbell™ from 2020-2022. Mr. Lesser was named an Up-and-Coming Lawyer by Massachusetts Lawyers’ Weekly in 2002. He was selected as a Massachusetts Super Lawyer in 2021, 2022, and 2023. He was selected as a Massachusetts Super Lawyers Rising Star in 2005 and 2010.

  • Brandeis University (B.A., cum laude, 1992)
  • Boston University (J.D., 1995)
  •  Named a Massachusetts Super Lawyer® in 2021 and 2022 by Thomson Reuters’s Massachusetts Super Lawyers® Magazine
  • Named a New England’s Top Rated Lawyer by ALM Media and Martindale-Hubbell™ in 2020, 2021 and 2022
  • Named a Super Lawyers® “Rising Star” in 2005 and 2010 by Thomson Reuters’s Massachusetts Super Lawyers® Magazine
  • Named an “Up and Coming Lawyer” by Massachusetts Lawyers’ Weekly in 2002
  • Member, American Bar Association
  • Member, The American Association for Justice
  • Member, Taxpayers Against Fraud
  • 1995, Massachusetts
  • 1997, U.S. District Court, District of Massachusetts
  • 2006, U.S. Court of Appeals, First Circuit


Thornton Law Firm was founded in 1978 by Michael Thornton and two other attorneys doing groundbreaking work for victims of mesothelioma and other asbestos-related diseases. Now a leading injury law firm in Massachusetts and one of the largest plaintiff law firms in New England, the firm has 19 attorneys representing thousands of clients in a wide variety of plaintiff-side work.

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