About Brien Investigative Services
Brien Investigative Services is a licensed, insured, and bonded private investigative firm serving the Commonwealth of Massachusetts. Veteran-owned and operated, BIS provides discreet, thorough, and fact-driven investigative services to attorneys, public agencies, and private clients.
Career & Investigative Experience
Professional Background
David C. Brien is a licensed private investigator and military veteran with over two decades of experience in corrections, investigations, and public safety.
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United States Marine Corps Service
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David honorably served on active duty in the United States Marine Corps from 1987 to 1991, including extensive overseas service in a combat Military Occupational Specialty during Operation Desert Shield and Operation Desert Storm. Following his honorable discharge, David began his career with the Massachusetts Department of Correction in 1993 as a Correction Officer.
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Massachusetts Department of Correction
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David’s career with the Department spanned 28.5 years, during which 15 years were spent in investigative assignments. He served his first 13 years at MCI–Cedar Junction (Walpole Prison), including five years selected for the Inner Perimeter Security (IPS) Team. In this role, David cultivated confidential informants, addressed major institutional security concerns, and conducted investigations into criminal activity involving both inmates and staff.
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Investigative Leadership & Command Roles​
Through successive promotions, David attained the rank of Captain and was selected to serve as Director of Investigations at Bridgewater State Hospital, where he led the IPS Team for four years. This assignment involved complex investigations concerning inmates with serious mental illness and high-risk institutional environments.
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David was later appointed Captain of the Internal Affairs Unit for the Southern Sector of the Massachusetts Department of Correction. In this role, he supervised a team of experienced investigators conducting administrative investigations across eight correctional institutions, overseeing matters involving more than 2,000 employees. Many of these investigations were conducted in collaboration with external law enforcement agencies.
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In addition to his investigative duties, David served for 20 years on the Department’s Special Reaction Team (SWAT) as a member of the precision marksmanship unit.
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Continued Military Service​
Continuing his military service, David enlisted in the Rhode Island Army National Guard in 2010 as an infantryman with the 182nd Infantry Regiment. In 2011, he deployed to Afghanistan in support of Operation Enduring Freedom. Upon returning stateside in 2012, he continued serving in the National Guard while completing his career with the Department of Correction.
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Brien Investigative Services
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In December 2021, David retired from the Massachusetts Department of Correction and founded Brien Investigative Services, where he now provides professional investigative support to bar advocates, defense attorneys and citizens throughout the Commonwealth of Massachusetts. David is a member in good standing with LPDAM (Licensed Private Detective Association of Massachusetts) and NALI (National Association of Legal Investigators).
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Brien Investigative Services is a licensed, insured, and bonded investigative firm located on the South Coast of Massachusetts, specializing in legal investigations throughout the entire Commonwealth.