The Contra Costa County Inmate Population
The Contra Costa County inmate population is reported through several official lenses. The Contra Costa County Office of the Sheriff runs the Martinez, West County, West County Reentry Treatment and Housing, Marsh Creek, and Custody Alternative operations. The Custody Services Bureau describes three detention facilities plus custody alternative, court security, and inmate transportation. For public data, the most useful county source is the sheriff's oversight reporting, which gives average daily population by facility or category. The state BSCC Jail Profile Survey is the California jail-population framework, and Vera's county profile adds historical comparison.
Counts rise or fall for different reasons. Arrest volume sends people first to Martinez Detention Facility for booking. Bail decisions, release orders, warrants, remands, medical or mental-health needs, and classification can move a person to West County, WRTH, Marsh Creek, or a custody alternative. A sentence to state prison removes the person from the Contra Costa jail count and places them in the CDCR CIRIS search system. Federal and immigration custody are separate again, so a single name search may need more than one official channel.
Contra Costa County Inmate Population Statistics
Sheriff oversight reports show the clearest current local trend. In 2025, average daily population was 430 at Martinez, 490 at West County, and 37 at Marsh Creek, for 957 across the three physical county jail facilities. The same report lists 651 for the Custody Alternative Facility category and 101 in Other. Those categories matter because custody alternatives manage people under court order, but they are not jail beds. Vera's 2022 profile reported an average jail population of 877, 15,464 jail admissions, 18,297 arrests, and 1,499 Contra Costa residents in state prison.
| Measure | Figure | Source / Year |
|---|---|---|
| Physical jail average daily population | 957 | Sheriff oversight report, 2025 |
| Custody Alternative Facility average daily population | 651 | Sheriff oversight report, 2025 |
| Annual bookings into Martinez | 26,000+ people | Sheriff office overview, inspected 2026 |
| County residents in state prison | 1,499 | Vera county profile, 2022 |
The BSCC Jail Profile Survey page is the statewide portal for county jail data and capacity reporting. The screenshot below shows that BSCC is the California source to check when comparing Contra Costa County inmate population figures with other counties.
Use BSCC for the state data system, but use sheriff oversight reports when the question is the latest local facility-by-facility average.
Contra Costa County Inmate Population Trends
The strongest recent trend is growth in both physical jail ADP and custody alternatives. From 2024 to 2025, Martinez rose from 411 to 430, West County rose from 460 to 490, and Marsh Creek fell from 41 to 37. The three physical jail facilities together rose from 912 to 957. Custody Alternative Facility ADP rose more sharply, from 495 to 651, which points to a larger group of people serving court-ordered sentences or monitoring outside a traditional jail bed.
| Year | Average Daily Population | Notes |
|---|---|---|
| 2022 | 877 average jail population | Vera profile also reports 15,464 jail admissions. |
| 2024 | 912 physical jail ADP | MDF 411, WCDF 460, MCDF 41 in sheriff oversight report. |
| 2025 | 957 physical jail ADP | MDF 430, WCDF 490, MCDF 37 in sheriff oversight report. |
| 2026 | 272 WRTH capacity opened | Sheriff WRTH page describes the new Richmond reentry and treatment building. |
The 2015 BSCC-hosted Jail Needs Assessment said Contra Costa had a low per-capita incarceration rate, 33 percent below the state average at that time, but still faced design and capacity pressure. The West County Reentry Treatment and Housing project grew out of that planning. The current WRTH page now describes a 272-person facility with medical, dental, reentry, and family reunification space for vulnerable custody populations.
Contra Costa County Jail Capacity
Capacity is not one clean number. Martinez has a 695 rated-capacity figure in BSCC-derived public jail listings, while the current sheriff facility page does not publish a rated capacity. West County is described by the sheriff as holding up to 1,096 incarcerated people in five housing units. WRTH adds up to 272 people on the West County campus. Marsh Creek's current sheriff page gives a maximum housing capacity of 154 and an average population of 70, while older materials used 188. Current page copy should prefer the sheriff's present number and treat older figures as historical context.
Capacity note: Custody Alternative Facility participants are part of population management, but they are not counted as traditional jail beds.
Contra Costa County Custody Makeup
Official research did not extract a current BSCC chart for pretrial versus sentenced, sex, race, or charge-level jail population shares. The record sources do show useful operational categories. Martinez is maximum security and the primary intake point for people booked in Contra Costa County. West County is a direct-supervision, co-educational, program-oriented campus. WRTH focuses on medical, mental-health, security, and reentry needs. Marsh Creek houses sentenced adults convicted of lesser crime classifications in a minimum-security setting. The Custody Alternative Facility handles court-ordered Work Alternative Program and Electronic Home Detention participants.
- Classification
- Jail screening that assigns housing, security level, and program placement under California Title 15 standards.
- Remand
- A court order placing or returning a person to custody.
- Custody alternative
- A court-ordered way to serve a sentence through approved work or electronic monitoring outside a jail bed.
- CDCR
- California Department of Corrections and Rehabilitation, the state prison system for sentenced prisoners.
Laws Governing Contra Costa County Jail Data
California law draws lines between public jail data, court records, state criminal-history files, and protected details. The Contra Costa County inmate population is visible through booking logs and custody tools because local law-enforcement records carry public-access rules, but those rules do not turn a jail roster into a full criminal-history report. Some arrest details can be withheld for safety, victim privacy, active investigation, or special statutory limits.
Key Statutes:
Government Code section 7920.000 identifies the California Public Records Act as the baseline public-records law.
Government Code section 7923.610 covers public access to specified contemporaneous arrest information, with safety and investigation limits.
Penal Code section 6030 requires BSCC minimum standards for local correctional facilities.
Government Code section 12525 makes custodial-death reporting to the Attorney General a public-record process with medical limits.
Search the Contra Costa County Inmate Population
The official county search starts with the Contra Costa In-Custody Locator. It is free and does not require login. The locator lets a user search by first and last name or by booking number. The sheriff's notice says the information represents the most recent information known to the Sheriff's Office and may change as a person moves through the judicial process. If a name does not appear, the notice directs users to contact the local jurisdiction. For Contra Costa jail custody, the Records & ID page lists Martinez Detention Facility inmate information at (925) 646-4493.
The In-Custody Locator search page shows the name and booking-number tabs used for Contra Costa County inmate search.
The locator is best for current custody. Recent arrest-log style records use the separate In-Custody Reports tool.
- Open the official In-Custody Locator and read the sheriff's warning about changing custody data.
- Select Name or Booking Number as the search path.
- Enter both first and last name for a name search, or enter the booking number for an exact search.
- Use the Detail link when a result appears, then check facility, bail, court date, and charge fields.
- If the person is not listed, try In-Custody Reports, call the inmate information line, or use court and CDCR channels.
Contra Costa County Inmate Lookup Fields
The county locator is narrow by design. It does not ask for race, age, sex, charge, or facility before the search. Name search requires both first and last name, which helps reduce broad result lists but can miss a person when the spelling is wrong. Booking number search is the best path when the number is available from a court paper, jail call, bond receipt, or recent report.
| Field Label | Type | Required | Notes |
|---|---|---|---|
| Search By: Name | Tab | Path selection | Activates the first and last name form. |
| Last Name | Text | Yes | Maximum length 25 characters. |
| First Name | Text | Yes | Maximum length 25 characters. |
| Search By: Booking Number | Tab | Path selection | Activates the booking-number form. |
| Booking Number | Text | Yes in that mode | Maximum length 20 characters. |
Contra Costa County Booking Records
The In-Custody Reports page is a separate official channel. It offers a report selector for Arrest Report and Incident Summary Report. The generated arrest report includes names, booking dates, DOB, release data, booking number, physical descriptors, case type, warrant fields, bail amounts, and charges. The report warning says arrest logs and calls-for-service records are summaries and that logs are removed from the sheriff website approximately 30 days after posting. It also warns that some suspect, location, victim, and incident details may be removed under California law.
The Contra Costa In-Custody Reports page is the official report dropdown for recent arrest and incident summaries.
When a person has been released or the online log has aged off, the Records & ID Unit is the local records fallback.
What Contra Costa County Inmate Records Show
A current locator detail can show the person's name, booking number, year of birth, gender, ethnicity, physical descriptors, arresting agency, arrest date and time, arrest type, facility, bail, court date, court location, case number, charges, and cleared date. The arrest report can show more log-style fields, including release out, release reason, case type, warrant number, warrant bail, and charge bail. A mugshot and housing unit were not observed in the inspected public detail page or arrest report.
| Field | What It Shows |
|---|---|
| Booking Number | Local numeric custody identifier used for exact search, mail, and deposit references. |
| Date In | Date booked or received into custody. |
| Facility Name | Where the person is held in the county jail system. |
| Total Bail Amount | Total bail or no-bail status when populated. |
| Court Date/Location | Next court setting and courthouse when listed. |
| Charges | Statute, level marker, and charge line tied to the booking or case. |
Contra Costa Jail vs State Prison
Contra Costa County jail records and CDCR prison records cover different points in a criminal case. The county jail search covers people arrested, booked, awaiting court, serving local sentences, or placed in county custody. CDCR CIRIS covers sentenced state prisoners after commitment to state prison. No adult CDCR state prison was found inside Contra Costa County in the official facility locator, so a state-prison transfer sends the search out of the county jail system.
| Question | County Jail | State Prison |
|---|---|---|
| Who runs it | Contra Costa County Office of the Sheriff | California Department of Corrections and Rehabilitation |
| Who is listed | Arrestees, pretrial detainees, local sentences, remands, county holds | People sentenced and committed to state prison |
| Where to search | In-Custody Locator and In-Custody Reports | CDCR CIRIS |
| When to switch | Current or recent county custody | After state-prison commitment or transfer |
State and Federal Inmate Search
Use CDCR CIRIS when the person has moved into California state prison. CDCR support for CIRIS is available through the Identification Unit at (916) 445-6713, Monday through Friday, excluding holidays, 8:00 a.m. to 4:30 p.m. Pacific. Use the Federal Bureau of Prisons inmate locator for federal sentenced custody and federal records from 1982 forward. Use ICE ODLS for immigration detention, where searches require either A-number plus country of birth or exact biographical data.
The CDCR CIRIS page is the official California search channel after a Contra Costa County jail case becomes a state-prison case.
CDCR is not a county jail roster, and it should not be used for a new Martinez booking unless the person has already been sentenced to state prison.
Contra Costa County Detention Facilities
The Contra Costa County inmate population is spread by role. Martinez is intake and maximum-security custody. West County is the large Richmond program campus. WRTH is the newer treatment and reentry building on that campus. Marsh Creek is the minimum-security sentenced facility near Clayton. Custody Alternative Facility handles work alternative and electronic home detention rather than ordinary jail housing.
- Martinez Detention Facility - primary intake, maximum-security custody, and county jail records starting point.
- West County Detention Facility - direct-supervision Richmond campus for adult men and women in county custody.
- West County Reentry Treatment and Housing - medical, mental-health, security-needs, and reentry housing on the West County campus.
- Marsh Creek Detention Facility - minimum-security sentenced population and vocational programming near Clayton.
- Custody Alternative Facility - Work Alternative Program and Electronic Home Detention for eligible court-ordered sentences.
Contra Costa County Inmate Population FAQ
How large is the Contra Costa County inmate population?
The 2025 sheriff oversight report lists 957 average daily population across Martinez, West County, and Marsh Creek. It also lists 651 for Custody Alternative Facility and 101 for Other. Those are not all the same kind of custody, so the safest reading separates physical jail beds from alternative custody categories.
How do I search Contra Costa County inmates?
Start with the official In-Custody Locator by name or booking number. If the person was recently arrested but is not in current custody, check In-Custody Reports. If the person was sentenced to state prison, use CDCR CIRIS instead of the county roster.
Can I find past Contra Costa County inmate records?
Recent arrest logs are posted for a limited window, and the research found an approximately 30-day removal note on the arrest report. Older or official records go through Records & ID, court criminal records, or the DA depending on whether the request is for jail custody, court case status, or formal charges.
Are federal or immigration detainees in the county roster?
The county roster is not a federal or ICE database. No current ICE-owned facility or adult CDCR prison was found inside Contra Costa County. Use BOP for federal custody and ICE ODLS for immigration detention when the person is not in county jail.