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 23, 2026 and October 9, 2026.
Plymouth County, Massachusetts, has about 542,000 residents (2024 Census Bureau estimate). A person kept in custody after an arrest in Plymouth County is held at the county jail, run by the Plymouth County Sheriff’s Department - MA POST Commission, 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: Plymouth County public records, Plymouth County arrest records, Plymouth County warrants, Plymouth County criminal records, Plymouth County court records, Massachusetts arrest records and Massachusetts inmate search.
Finding Someone in Custody in Plymouth County
A person kept in custody after an arrest in Plymouth County is held at the county jail, run by the Plymouth County Sheriff’s Department - MA POST Commission, whichever agency made the arrest.
SearchSystems opened and checked the jail page of the Plymouth County Sheriff’s Department - MA POST Commission at mapostcommission.gov/current-agency/plymouth-county-sheriffs-depart... (page title: Plymouth County Sheriff’s Department | MA POST Commission), 84 State Street, 2nd Floor, Boston, MA 02109, which answered when SearchSystems opened it on October 9, 2026.
That page is the office's jail information page rather than a roster.
The Plymouth County Jail by the Numbers
On an average day in 2025 the jail held about 1,040 people, down from about 1,090 in 2019. Its rated capacity in 2023, the last year with a capacity figure, was 1,140 beds, and it ran at 46 percent of it that year. The figures are from the Vera Institute of Justice's Incarceration Trends data.
Plymouth County has about 542,000 residents (2024 Census Bureau estimate), so the jail holds about 19 people for every 10,000 residents.
Who Books People Into the Plymouth County Jail
The Plymouth County Sheriff’s Department - MA POST Commission and the agencies that report for Brockton and Bridgewater Town make the arrests that end in a booking in Plymouth County.
The FBI's agency list also places two campus police departments, one state agency and one state police unit in Plymouth County (the arrest records guide names each one).
The largest arrest counts reported to the FBI were Brockton's 2,124 for 2025, Plymouth's 652 for 2025 and Wareham's 638 for 2025.
Together, the 27 agencies in Plymouth County with all twelve months of 2025 on file reported 7,201 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 Plymouth County 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 Plymouth County serves the sentence in a facility of the Massachusetts Department of Correction, whose inmate locator is at mass.gov/how-to/find-someone-housed-in-a-massachusetts-prison.
Frequently Asked Questions
How do I find an inmate in Plymouth County?
Ask the Plymouth County Sheriff’s Department - MA POST Commission; its jail page SearchSystems verified is at mapostcommission.gov.
How many people are in the Plymouth County jail?
About 1,040 on an average day in 2025, the latest year in the Vera Institute's jail data, against a rated capacity of 1,140 beds.
Where do people sentenced to prison in Plymouth County go?
To a facility of the Massachusetts Department of Correction; its inmate locator is at mass.gov.
Is this the official Plymouth County website?
No. SearchSystems.net is an independent public records guide, online since 1997. It links to the official county, court and state offices described above and does not hold records, charge for them or take requests.