Donahue Investigative Services is headquartered in Salem, NH — founded by a former Salem, NH police officer with 34 years of law enforcement experience. Local knowledge. Dual-licensed in NH and MA. Free consultation.
Salem NH is our home base. Mark J. Donahue served as a Salem, NH police officer for years before building a 34-year law enforcement career that included the DEA Task Force and NH AG’s Gang Task Force. He knows Salem’s streets, courts, businesses, and community — and holds dual licensure in NH and MA for the many cases that cross the southern border into Massachusetts.
Private Investigation Services in Salem, NH
As Salem-based investigators, we bring genuine local knowledge to every case. We know Rockingham County courts, the local business community, and the geographic realities of a town that sits squarely on the NH/MA border. Methuen is next door. Lawrence is a short drive. Cases that cross the state line are routine for us — and our dual licensure means we handle them without referrals.
Cheating Spouse Investigation
Covert infidelity surveillance across Salem and the greater southern NH and northern MA area.
Surveillance Investigations
Workers’ comp fraud, insurance abuse, and corporate misconduct in Salem and surrounding towns.
Child Custody Documentation
Parental behavior documentation for Rockingham County Family Division and cross-border MA matters.
Background Checks & Skip Tracing
People locate, skip tracing, and background investigations for Salem-area clients and businesses.
Corporate Investigations
Employee theft, fraud, and due diligence for Salem and southern NH businesses.
Litigation Support
Process serving, witness location, and evidence collection for Rockingham County attorneys.
Meet the Investigator — Mark J. Donahue
Founder & Principal Investigator — Salem, NH
Mark J. Donahue is a former Salem, NH police officer with a 34-year law enforcement career. His assignments included service on the DEA Task Force, the Internet Crimes Against Children (ICAC) Task Force, and the NH Attorney General’s Gang Task Force — all federal-level investigations requiring sophisticated surveillance, evidence documentation, and inter-agency coordination. That background is the foundation of Donahue Investigative Services. Every case is handled with the same discipline and evidence standards Mark applied throughout his career in law enforcement.
The NH/MA Border Advantage
Salem, NH sits directly on the Massachusetts border. Methuen and Lawrence, MA are neighbors. For a private investigation firm, this geography matters: cases regularly cross the state line — subjects who live in Salem and work in Methuen, custody disputes involving parents who relocated across the border, workers’ comp claimants performing undisclosed labor in MA.
We hold active PI licenses in both New Hampshire and Massachusetts, which means we follow cases wherever they lead. No hand-offs, no referrals, no jurisdictional blind spots.
Southern NH and Northern MA Communities We Serve
From Salem we serve the full southern NH corridor — Derry, Londonderry, Windham, Pelham, Hudson, Nashua — and cross-border into Methuen, Lawrence, Haverhill, Andover, North Andover, and the greater Merrimack Valley.
Frequently Asked Questions
Is Donahue Investigative Services based in Salem, NH?
Yes. We are headquartered in Salem, NH. Mark J. Donahue is a former Salem, NH police officer with 34 years of law enforcement experience, including the DEA Task Force and NH AG’s Gang Task Force. Salem is our home base — we know the town, the courts, and the community.
What PI services are available in Salem, NH?
From Salem we offer cheating spouse surveillance, child custody documentation for Rockingham County Family Division, workers’ comp fraud investigations, background checks and skip tracing, corporate investigations, missing persons locate, and litigation support for southern NH attorneys. We also hold a MA license for cross-border cases.
Does Salem NH border Massachusetts — do you cover both states?
Yes. Salem borders Methuen and Lawrence, MA. We hold active licenses in both NH (#M-2025-0424) and MA (#LP1599A), so cases that cross the state line are handled without referrals or jurisdictional gaps. This dual-state coverage is a core advantage of working with a Salem-based firm.
Free confidential consultation: 603-785-2800 — NH License #M-2025-0424 · MA License #LP1599A
