Merrill's Investigations and Security Services

For 25-years, Merrill’s has built its reputation as the best, most reliable and easiest to work with private investigator service in Maine and northern New England.

Merrill's Investigation & Security was founded by Charles A. Merrill in 1985 after a distinguished 20-year career with the Maine Warden Service. The Company has operated continuously since that time. In 1999 the company added security and executive protection services to its suite of services. In 2004, after a ten year affiliation with Merrill’s and 21 years in law enforcement, Michael C. Harrington Sr. purchased the company. Under Mr. Harrington’s leadership the Company has grown exponentially and has developed into a regional powerhouse.

Maine's private investigator - Merrill's Investigations and Security operates throughout Northern Maine, Southern Maine, New Hampshire, Massachusetts, Vermont or anywhere you need a qualified investigator.

Today the company is one of the largest providers of investigative and security services in Maine. It provides workers’ compensation and surveillance services to major insurance companies in Maine, New Hampshire and Massachusetts.  Merrill's also provides investigative services to a range of corporations and law firms throughout Maine. Additional services in arson, accident and canine-assisted investigations are offered by Merrill’s, as are executive protection and high-end security and advance team operations.

With a combined experience of more than 475 years, Merrill’s leads the industry in experience, expertise and professionalism. Merrill’s resource depth makes it able to provide clients with one-stop shopping for investigative services across the northeast – something no other firm can match.

As Maine's largest investigative services company, we have the resources to efficiently and effectively lean in on cases anywhere in the northeast.  Every Merrill’s investigator is familiar with Maine law and has provided testimony in trials and at other types of hearings. Hand-picked for their experience, tenacity and professionalism, Merrill’s investigators hail from the region’s most respected law enforcement agencies, including Maine Warden Service, Maine State Police, and Maine Drug Enforcement Agency. All are equipped with and trained in the effective use of leading-edge investigative and surveillance techniques.

At Merrill’s the primary mission is to provide clients with cost-effective, discreet and professional investigations, conducted in a timely manner. In every case Merrill's provides accurate and professional written reports that describe events as they happened and, where possible, include videotaped, photographic and/or other recorded documentation.

All Merrill’s investigator s are intimately familiar with the geography and culture of the region. Most have worked in many areas of the state during their careers in law enforcement and private investigation. Merrill’s has developed many contacts across the northeastern states who serve as invaluable and un-matched resources in gathering information to expedite client investigations.

Equal Opportunity

It is the policy of Merrill’s Investigations to give equal employment opportunity to all qualified persons, and to provide that all individuals be recruited, hired, assigned, advanced, compensated and retained on the basis of their qualifications, and treated equally in these and all other respects without reference to race, color, national origin, religion, sex, marital status, disability, age or sexual orientation.

Americans with Disabilities Act and Maine Human Rights Act

Merrill’s does not discriminate against qualified individuals with a disability in such areas as job applicants, compensation, hiring, advancement, training and discharge.  Reasonable accommodations will be made for individuals who have a disability.


Private Investigation | Security & Protection | Search & Surveillance




Our mission is to provide our clients with timely, accurate intelligence that makes a difference.

  • Videos
  • Photographs
  • Reports

All investigations are performed with attention to discretion, objectivity and professionalism.

A+ Rated by B.B.B.

Merrill's is an A+ rated BBB member!

Client Log-in

Click here to access Merrill's case management system. Or call anytime: (207) 685-7309

Stay Informed


What our customers are saying...

"Thanks for making me look good, Merrill's!" - Claims Adjuster


"The guys at Merrill's are total pros! They captured images and video that were critical to helping me close the biggest case of my career." - VP, Insurance Industry


"It's one thing to tell a jury they're being lied's another thing to show a jury the video! Thanks, Merrill's." - Claims Adjuster