Reviewed and updated October 9, 2026 by the SearchSystems.net editorial team. The arrest counts are the ones each agency reported to the FBI, as the FBI held them on October 8, 2026. The jail figures are from the Vera Institute of Justice's Incarceration Trends data. Every office link was opened and checked against the office's own site between September 24, 2026 and October 2, 2026.
Portsmouth, New Hampshire, in Rockingham County, has about 23,000 residents (2024 Census Bureau estimate). A person kept in custody after an arrest in Portsmouth is held at the county jail, run by the Rockingham County Sheriff's Office, and the jail's record of each person held is a public record. This guide says where to look for someone in custody, what the jail holds and who books people into it.
This guide covers the search, the jail, who books people, state prison and common questions.
Related guides: Portsmouth public records, Rockingham County inmate search, Portsmouth arrest records, Portsmouth warrants, Portsmouth criminal records, Portsmouth court records, New Hampshire arrest records and New Hampshire inmate search.
Finding Someone in Custody in Portsmouth
The county jail, run by the Rockingham County Sheriff's Office, holds everyone kept in custody after an arrest in Portsmouth, from every agency.
SearchSystems opened and checked the jail page of the Rockingham County Sheriff's Office at rockso.org (page title: Rockingham County Sheriff's Office), which answered when SearchSystems opened it on September 24, 2026.
That page is the office's jail information page rather than a roster.
The Rockingham County Jail by the Numbers
On an average day in 2019 the jail held about 140 people. Its rated capacity in 2019 was 402 beds, and it ran at 34 percent of it that year. The figures are from the Vera Institute of Justice's Incarceration Trends data.
Rockingham County has about 322,000 residents (2024 Census Bureau estimate), so the jail holds about 4 people for every 10,000 residents.
Who Books People Into the Rockingham County Jail
The Rockingham County Sheriff's Office and the agency that reports for Portsmouth (filed by the FBI as Portsmouth Police Department) make the arrests that end in a booking in and around Portsmouth.
The FBI's agency list also places one more agency in Rockingham County: the Rockingham County State Police (state police).
The largest arrest counts reported to the FBI were Salem's 996 for 2025, Derry's 732 for 2025 and Hampton's 609 for 2025.
Together, the 35 agencies in Rockingham County with all twelve months of 2025 on file reported 5,812 arrests to the FBI that year. Those kept in custody were booked into the county jail; a person cited and released at the scene was not.
The counts, agency by agency and year by year, are in Portsmouth arrest records.
From the Jail to State Prison
The jail holds people awaiting trial and people serving short sentences. A person sentenced to prison in Rockingham County serves the sentence in a facility of the New Hampshire Department of Corrections, whose inmate locator is at business.nh.gov/inmate_locator.
Frequently Asked Questions
How do I find an inmate in Portsmouth?
Ask the Rockingham County Sheriff's Office; its jail page SearchSystems verified is at rockso.org.
How many people are in the Rockingham County jail?
About 140 on an average day in 2019, the latest year in the Vera Institute's jail data, against a rated capacity of 402 beds.
Where do people sentenced to prison in Rockingham County go?
To a facility of the New Hampshire Department of Corrections; its inmate locator is at business.nh.gov/inmate_locator.
Is this the official Portsmouth website?
No. SearchSystems.net is an independent public records guide, online since 1997. It links to the official city, county, court and state offices described above and does not hold records, charge for them or take requests.