Strategic Research
- Based in Cambridge, MA and is headed by a former investigative reporter. They specialize in complex business litigation and due diligence.
- http://www.srresearch.com/

Nardizzi & Associates, Inc.
- Boston firm specializes in business litigation and intellectual property matters. Also handles wrongful convictions cases on both pro bono and fee basis.
- http://www.nardizzi.com

TM Morgan Private Investigator Massachusettes
- Handles domestic cases and surveillance in the Worcester area.
- http://www.tmmorgan.com

Bentley Associates, Inc.
- Firm conducts domestic and international investigations. Based in Andover.
- http://www.bentley-associates.com/

GUmina Investigations
- Private investigator services the Cape Cod area.
- http://home.comcast.net/%7egumina_pi/

Wink Investigations
- Martha's Vineyard-based investigator handles security consulting and executive protection.
- http://www.winkinvestigations.com

Discovery Services
- Springfield-based firm specializing in domestic surveillance and insurance claim investigations.
- http://www.discovery-services.net

Orion Investigations
- Based in Stoneham, the firm provides investigations for the legal profession and insurance industry. They also handle domestic cases.
- http://www.orioninvestigations.net

The Simmons Agency, Inc.
- Private firm dealing in individual and corporate cases. Offices in Boston and Cape Cod.
- http://www.simmonsagency.com

Read Investigative Services
- Agency is based in Mashpee, and focuses on auto insurance investigations, surveillance and workers comp cases.
- http://capecodpi.com