Research Report
Incarceration Trends Pretrial Probation June 25, 2026
Implementing a Mobile Probation Unit
In the United States, more adults are under probation supervision than are held in prisons and jails or under parole supervision combined. In 2023, about 3.1 million, or 1 in 85 US adults, were subject to probation supervision. Probation violations, owing to technical violations or new offenses, are a significant driver of jail incarceration. With support from the MacArthur Foundation’s Safety and Justice Challenge (SJC), Palm Beach County, Florida, established its Mobile Probation Unit (MPU) to improve access to probation services, reduce probation violations, and limit jail reincarceration for people on probation.
Why This Matters
Probation departments play a critical role in determining whether people remain safely in the community or cycle back into local jails for technical violations or new arrests. Yet many people face barriers to complying with probation requirements, including lack of transportation, unstable housing, and work and family obligations. These challenges are especially pronounced in a county as dispersed as Palm Beach, where accessing probation offices can involve long travel times and multiple transfers on public transit. Providing flexible, accessible, and supportive probation services can increase compliance, reduce unnecessary jail incarceration, and improve long-term outcomes for people on probation.
What We Found
The Mobile Probation Unit was developed to bring probation services directly into communities, reducing logistical barriers that often lead to violations. Stakeholders reported several key successes associated with the intervention. The MPU was expanded beyond its initial pilot program, indicating strong early support and use. Its convenience contributed to consistent use by many people on probation, and stakeholders reported a reduction in probation violations after the MPU was implemented. Implementing the MPU also strengthened collaboration between criminal legal system stakeholders and community partners. Challenges associated with developing the MPU included inconsistent staffing of the unit, limited success reaching parts of the county most affected by racial disparities in criminal legal system involvement, and limited availability of supportive services.
How We Did It
For this case study, we conducted semistructured interviews with 16 key criminal legal system stakeholders in Palm Beach County and 10 people on probation who used the MPU; reviewed SJC progress reports and other documentation related to the development and implementation of the MPU; analyzed program data provided by local stakeholders; and examined jail population data collected by the Institute for State and Local Governance. We analyzed transcripts and notes from the interviews using NVivo qualitative analysis software, applying a codebook developed to identify themes related to the implementation of the MPU and other local criminal legal system reform efforts.
