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.
Barnstable County, Massachusetts, has about 233,000 residents (2024 Census Bureau estimate). A person kept in custody after an arrest in Barnstable County is held at the county jail, run by the Barnstable County Sheriff’s Office - 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: Barnstable County public records, Barnstable County arrest records, Barnstable County warrants, Barnstable County criminal records, Barnstable County court records, Massachusetts arrest records and Massachusetts inmate search.
Finding Someone in Custody in Barnstable County
The county jail, run by the Barnstable County Sheriff’s Office - MA POST Commission, holds everyone kept in custody after an arrest in Barnstable County, from every agency.
SearchSystems opened and checked the jail page of the Barnstable County Sheriff’s Office - MA POST Commission at mapostcommission.gov/current-agency/barnstable-county-sheriffs-office (page title: Barnstable County Sheriff’s Office | MA POST Commission), 84 State Street, 2nd Floor, Boston, MA 02109, which answered when SearchSystems opened it on September 30, 2026.
That page is the office's jail information page rather than a roster.
The Barnstable County Jail by the Numbers
On an average day in 2025 the jail held about 270 people, down from about 290 in 2019. Its rated capacity in 2023, the last year with a capacity figure, was 547 beds, and it ran at 31 percent of it that year. The figures are from the Vera Institute of Justice's Incarceration Trends data.
Barnstable County has about 233,000 residents (2024 Census Bureau estimate), so the jail holds about 12 people for every 10,000 residents.
Who Books People Into the Barnstable County Jail
The Barnstable County Sheriff’s Office - MA POST Commission and the agency that reports for Barnstable Town make the arrests that end in a booking in Barnstable County.
The FBI's agency list also places these agencies in Barnstable County: Cape Cod Community College (campus police); the Barnstable County State Police (state police).
The largest arrest counts reported to the FBI were Barnstable Town's 1,192 for 2025, Yarmouth's 571 for 2025 and Falmouth's 452 for 2025.
Together, the 14 agencies in Barnstable County with all twelve months of 2025 on file reported 3,650 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 Barnstable 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 Barnstable 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 Barnstable County?
Ask the Barnstable County Sheriff’s Office - MA POST Commission; its jail page SearchSystems verified is at mapostcommission.gov.
How many people are in the Barnstable County jail?
About 270 on an average day in 2025, the latest year in the Vera Institute's jail data, against a rated capacity of 547 beds.
Where do people sentenced to prison in Barnstable County go?
To a facility of the Massachusetts Department of Correction; its inmate locator is at mass.gov.
Is this the official Barnstable 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.