1,669,979
Estimated residents
Middlesex County's population estimate as of July 1, 2025.
Source: U.S. Census Bureau, 2025 estimatePublic Reference
Middlesex County Justice Data
A sourced snapshot of the population, court system, caseload, and arraignment data that describe the work of the District Attorney's Office. Last updated July 18, 2026.
2024 Reference
The scale of the work matters.
Middlesex County is the largest county in Massachusetts. The figures below distinguish county-wide context from the District Attorney's Office's own 2024 case and bail reporting.
Key statistics
54
Cities and towns
The Middlesex District Attorney's Office identifies 54 communities within its service area.
Source: Middlesex District Attorney's Office18
Courts served
The office reports work across 12 district courts, 4 juvenile courts, and 2 superior courts.
Source: Middlesex District Attorney's Office31,509
Active cases in 2024
The office reported this number of active cases between January 1 and December 31, 2024.
Source: Middlesex County case data, 202418,548
New cases arraigned
These cases were newly arraigned in Middlesex County courts during calendar year 2024.
Source: Middlesex County case data, 202417,271
District Court arraignments
The office reported this number of cases arraigned in Middlesex County District Courts during 2024.
Source: Middlesex County bail data, 202475.89%
No cash-bail request
After cases disposed at arraignment were excluded, the office reported that it did not request bail in 10,338 of 13,623 remaining District Court cases.
Source: Middlesex County bail data, 2024829
Held without bail requested
The office reported these requests in cases involving murder charges, fugitives from justice, or pending dangerousness determinations.
Source: Middlesex County bail data, 2024