Middlesex County Inmate Population
The county jail count is reported through Massachusetts sheriff population reports, not through a live public roster on the Middlesex Sheriff's Office website. The Massachusetts Sheriffs' Association county population reports are the clearest public source for Middlesex County inmate population data. Those reports separate people in direct custody from people supervised outside secure jail beds. That distinction matters because a custody count is not the same as probation, electronic monitoring, or a community program count.
The local custody point is the Middlesex Jail & House of Correction in Billerica. The sheriff describes the jail as holding men awaiting trial, men serving local sentences of up to two and a half years, and women classified to the office's pre-release center. State prison facilities physically located in Middlesex County, including MCI-Shirley and Northeastern Correctional Center, are part of the Massachusetts Department of Correction system. FMC Devens is federal and is counted through the Federal Bureau of Prisons, not the county sheriff.
Middlesex County Inmate Population Statistics
The May 2025 sheriff population report listed a Middlesex custody average daily population of 751.00. The same report listed a supervised population average daily population of 729.00. Research also found a Census 2020 vintage Prison Policy Initiative locator entry listing 900 prisoners for the Middlesex County Jail & House of Correction, but the current rated capacity was not located on the sheriff's facility page. That older figure should be read as a historical locator value, not a current operating limit.
The MSA population report index is the source to check for new monthly reports. Its county reports are more reliable for the Middlesex County inmate population than unofficial roster mirrors because they are built from sheriff reporting rather than scraped pages.
| Measure | Figure | Source and Date |
|---|---|---|
| County custody ADP | 751.00 | MSA Average Daily Population Counts, May 2025 |
| Supervised population ADP | 729.00 | MSA Average Daily Population Counts, May 2025 |
| County jail locator count | 900 prisoners | Prison Policy Initiative correctional facility locator, Census 2020 vintage |
| Current annual bookings | Not located | Official Middlesex sources reviewed |
The official county population reporting page is shown in the Massachusetts Sheriffs' Association screenshot source.
That index is useful when a current roster is unavailable because it gives a county-level population trail over time.
Middlesex County Custody Breakdown
The May 2025 report shows that pretrial custody made up most of the secure Middlesex County inmate population. Pretrial males accounted for 477.00 ADP, while sentenced males accounted for 259.00 ADP. Sentenced females were listed at 14.00 ADP, and pre-arraignment male safekeeps were listed at 1.00 ADP. The report showed no ADP for federal, DOC reentry, or Section 35 categories in that Middlesex custody table.
| Category | ADP | What It Means |
|---|---|---|
| Pretrial males | 477.00 | Held before case disposition |
| Sentenced males | 259.00 | Serving local jail or house of correction sentences |
| Sentenced females | 14.00 | Classified to local custody or pre-release pathways |
| Pre-arraignment male safekeeps | 1.00 | Held before court processing |
Custody counts rise and fall with arrests, bail decisions, court calendars, sentences, transfers, and release orders. A person may leave the county jail count after release, after transfer to MADOC, after transfer to a federal facility, or after placement into a supervised non-secure category. That is why the Middlesex County inmate population should be read as a monthly picture, not a fixed head count.
Middlesex County Inmate Population Trends
The research found one firm current reporting point, the May 2025 MSA count, and a dated COVID-era comparison from public sheriff statements. In 2020, Sheriff Peter Koutoujian reported that the jail population fell from 787 on March 12 to 594 by early May. The reported causes included electronic monitoring, bail review, fewer arrests, and court and law-enforcement actions. That 2020 figure is useful as dated context, but it is not a current count.
| Date | Population Figure | Use |
|---|---|---|
| March 12, 2020 | 787 | Historical public statement before early pandemic reduction |
| Early May 2020 | 594 | Historical public statement after reduction measures |
| May 2025 | 751.00 custody ADP | MSA monthly county population reporting |
Monthly MSA reports run from 2012 through 2026 on the reporting page. Exact month-to-month trend work should cite the specific PDF used for each month. Without that PDF extraction, the safer Middlesex County inmate population statement is that May 2025 is a captured current value and the 2020 drop is historical context.
Laws Governing Middlesex Jail Data
Massachusetts law explains why some jail records can be requested and why some details may still be redacted. The sheriff has custody and control of county jails under state law, correctional superintendents must keep institutional records, and the Public Records Law gives the public a way to request non-exempt records. These rules do not create a public web roster for Middlesex County inmate population searches, but they do support formal requests for releasable records.
Key Statutes:
M.G.L. c. 66, section 10 gives the public a process to request non-exempt public records.
M.G.L. c. 126, section 16 places county jails and houses of correction under sheriff custody and control.
M.G.L. c. 127, section 2 requires keepers of correctional institutions to keep records.
34 U.S.C. section 60105 governs death-in-custody reporting for deaths during arrest, transport, or correctional custody.
Search Middlesex County Inmates
No current public Middlesex Sheriff's Office jail roster or inmate-search portal was located on the official sheriff website during the research sweep. That changes the search workflow. For local jail custody, start with the Middlesex Jail & House of Correction phone line and the sheriff's public-records channel. For a person who has moved to a Massachusetts prison, use the MADOC inmate lookup instructions and VINELink. For federal custody at FMC Devens or another federal facility, use the BOP inmate locator.
- Decide whether the person is likely in county jail, state prison, federal custody, or immigration custody.
- For recent local custody, call the Middlesex Jail & House of Correction at 978-667-1711 with the full name, date of birth, arrest date, and arresting agency if known.
- For a formal jail record, request records from the Middlesex Sheriff's Office Records Access Officer and describe the records and preferred format.
- For sentenced state prisoners, search MADOC through VINELink by full first and last name or commitment number.
- For federal custody, search by BOP register number or name through the BOP locator.
Because no online county roster was found, the county jail row below is a fallback table, not a portal-field table.
| Channel | Input | Best Use |
|---|---|---|
| Jail phone | Full name, DOB, arrest date, agency | Practical custody-status routing |
| MSO public records | Reasonable record description and preferred format | Booking or custody records not posted online |
| MADOC/VINELink | Full first and last name or commitment number | Sentenced Massachusetts prison custody |
| BOP locator | Name or federal identifier | Federal custody, including Devens when listed |
Middlesex County Inmate Record Fields
A Middlesex County inmate record request should be precise because the sheriff's site does not publish a searchable profile page. Useful request terms include booking number, control number, arresting agency, booking date, charge as booked, court of jurisdiction, bail status, release or transfer date, and booking photograph if maintained and releasable. The sheriff may redact material under public-records exemptions.
| Field | What to Ask For |
|---|---|
| Identity | Name, aliases, age or date of birth if releasable |
| Booking data | Booking date, control number, custody status, and facility |
| Charge data | Arrest offense as booked and court of jurisdiction |
| Bail or release | Bail status, release date, or transfer date when public |
| Booking photo | Photo if maintained and not withheld after exemption review |
Middlesex County Jail vs Prison
Readers often search the county jail for someone who is no longer in county custody. The Billerica jail covers pretrial and local sentence custody. MADOC covers criminally sentenced state prisoners. BOP covers federal custody. ICE ODLS covers immigration custody records when ICE has a custody record. Matching the system to the custody type is the fastest way to avoid a false no-result.
| Custody Type | Agency | Lookup Path |
|---|---|---|
| Pretrial or local sentence | Middlesex Sheriff's Office | Jail phone and public-records request |
| State prison sentence | Massachusetts Department of Correction | MADOC/VINELink |
| Federal sentence or BOP custody | Federal Bureau of Prisons | BOP inmate locator |
| Immigration custody | U.S. Immigration and Customs Enforcement | ICE Online Detainee Locator System |
The MADOC lookup source is shown in the Mass.gov inmate finding page screenshot source.
That state page is relevant only after custody shifts from the county sheriff to the state prison system.
Middlesex County Detention Facilities
The facility map for Middlesex County includes one primary county jail, two state prison facilities, and one federal medical center. Each has a different lookup path. The county jail page should be used for local custody basics, while state and federal pages should be read as separate custody systems.
- Middlesex Jail & House of Correction holds local pretrial detainees, local sentenced men, and women classified to pre-release.
- MCI-Shirley is a MADOC medium-security prison for criminally sentenced males.
- Northeastern Correctional Center is a MADOC minimum and pre-release facility for criminally sentenced males.
- Federal Medical Center Devens is a BOP federal medical center with an adjacent minimum-security camp.
Middlesex Booking and Bail
Booking is the jail intake process after arrest or commitment. Middlesex-specific public pages do not publish a full intake manual, but the research supports a conservative sequence: identity and paperwork review, property and money inventory, medical and security screening, control-number handling, housing classification, and communication access after housing assignment. Massachusetts law also requires correctional institutions to keep records of prisoners' money and property.
Bail at the Billerica jail has a narrow official window. The sheriff's jail FAQ states that bail must be posted at the Visiting Center between 6:30 p.m. and 7:00 p.m., no later than 7:00 p.m., Monday through Sunday. Bail is cash only, and the person posting bail must show a valid government-issued photo ID. A hold from another court, agency, probation matter, federal authority, or immigration process can still block release.
Middlesex Inmate Search Terms
Several short terms appear in jail, court, and prison records. Clear definitions reduce wrong searches.
- Pretrial
- Custody before a criminal case is finished.
- House of correction
- A Massachusetts county facility for local sentences, generally up to two and a half years.
- Commitment number
- A MADOC identifier used in prison lookup.
- Detainer
- A hold or notice from another agency that may affect release.
- Classification
- The custody or security assignment used for housing and program placement.
Middlesex County Inmate Population FAQ
How big is the Middlesex County inmate population?
The May 2025 MSA report listed 751.00 custody ADP for Middlesex County. It also listed 729.00 supervised population ADP. Those figures come from county sheriff population reporting and should be cited by month.
Does Middlesex County have an online jail roster?
No current official Middlesex Sheriff's Office public jail roster was located in the research. The practical local search path is the jail phone line and a public-records request when a formal record is needed.
Where are sentenced state prisoners searched?
State prison custody is searched through MADOC/VINELink. MCI-Shirley and Northeastern Correctional Center are state facilities, so they do not use the county jail roster path.
Where are federal inmates searched?
Federal inmates are searched through the BOP inmate locator. FMC Devens is the federal facility identified in Middlesex County, and county sheriff records do not cover BOP custody.