David Losier is a partner in the firm’s Business Litigation and White Collar Criminal Defense groups. His practice includes both complex civil litigation and felony criminal matters, and he represents individuals and companies in state and federal investigations. David brings his 30-plus years of experience to represent officers of both public and private companies responding to allegations of breaches of fiduciary duty, misrepresentation, or fraud.

David’s cases often involve economic espionage, tax fraud, and health care fraud – including parallel civil/administrative and criminal proceedings. Additionally, David often is asked by directors or officers to coordinate and lead internal corporate investigations. He also represents a variety of individuals and companies in employment litigation involving non-competition, non-disclosure, and wage payment issues. Additionally, he has successfully represented several secondary, college, and graduate school students in disciplinary actions brought before school judiciary panels and has successfully resolved related criminal cases facilitating the students’ continued enrollment in school.

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J.D., cum laude, Suffolk University Law School, 1992

B.S., Colby College, 1989



U.S. District Court for the District of Massachusetts

U.S. Court of Appeals for the First Circuit

honors & awards

AV® Preeminent Rating by Martindale-Hubbell

Massachusetts Rising Stars (2006)

community involvement

Boston Bar Association

  • Criminal Section Steering Committee

Middlesex Partnership for Youth

  • Board Member

Acton Boxboro Youth Hockey Association

  • Board Member and Coach


  • Lead counsel for national plastic manufacturer successfully defending charges of unfair competition and wrongful use of confidential trade secrets.
  • Counsel to prominent Boston-based graduate school leading an internal investigation into allegations of academic integrity violations.
  • Lead counsel directing an internal investigation for a national tractor trailer school in response to allegations of embezzlement and fraud.
  • Lead counsel to national rubber manufacturer successfully defending contract and negligence-based claims.
  • Lead counsel for criminal defendants and college students, obtaining dismissal of criminal charges and facilitating students continued attendance at prominent Massachusetts colleges.
  • Successfully represented prominent medical professional against criminal charges and secured ultimate dismissal of charges and declination of action by governing professional board of registration.
  • Lead counsel in an internal investigation of a regional accounting firm and successfully represented client in a federal criminal investigation resulting in no criminal charges.


American Bar Association

Boston Bar Association

Massachusetts Bar Association



“SJC to weigh Wiretap Act protections for website visitors,” Massachusetts Lawyers Weekly, March 2024

“Reviews of New Instruction on Eyewitness ID Favorable,” Massachusetts Lawyers Weekly, November 2015

“Withdrawing guilty pleas: instrument for justice or shopping for sentences?,” Boston 25 News, May 2015

Jay Severin Show, Interviewed, WTKK, March 2010

Jay Severin Show, Interviewed, WTKK, July 2007

“Slaying Victim Had Fled a Troubled Past,” Boston Globe, November 2004

speaking engagements

“Identification Evidence in Criminal Trials: Recent Law and Current Legal Challenges,” Speaker, Boston Bar Association, December 2015

“Subpoenas and Search Warrants,” Moderator, Boston Bar Association Panel Discussion, November 2011

“The CSI Effect: Fact or Fiction?” Moderator, Boston Bar Association Criminal Law Section Event, April 2011