Effect of Specialty Mental Health Probation on Public Safety Outcomes: A Matched Trial

Importance: Probation has become a cornerstone of efforts to reduce mass incarceration. Although understudied, specialty probation could improve outcomes for the overrepresented group of people with mental illness.

Objective:  To test whether specialty probation yields better public safety outcomes than traditional probation.

Setting:  Two urban agencies that exemplify specialty and traditional probation.

Design: Quasi-experiment (2006-2013) with group matching on age, gender, ethnicity, probation time, and offense. Probationers and officers were assessed three times (retention = 85-90%); follow-up records also obtained. 

Participants: Eligibility criteria: age 18-65, English-speaking, mental health problems. As a group, specialty (n= 183; 74% of eligible) and traditional (n= 173; 57% of eligible) participants were diverse men and women with serious mental health problems and functional impairment.

Intervention:  Specialty probationers were assigned to small, homogeneous caseloads supervised by expert officers. Data indicate specialty officers had better relationships with probationers, participated more in probationers’ treatment, and relied more on positive compliance strategies than traditional officers.   

Main Outcome Measure(s): Violence over one year (source: probationer report, officer report, records).  Re-arrest over two-to-five years (source: FBI records). 

Results: Machine learning algorithms were combined with targeted-maximum likelihood estimation, a double robust estimator that accounts for associations between confounds and both treatment assignment and outcomes. Although specialty probation had no significant effect on violence (OR = 0.97; CI = 0.69, 1.36), the odds of re-arrest were 2.68 times higher for traditional- than specialty-probationers (CI = 1.86, 3.84; p <.0001). At two years, estimated probabilities of re-arrest were 28.6% (specialty) and 51.8% (traditional). Survival analyses indicate arrest effects endured up to five years.

Conclusions and Relevance: Despite no specific effect on violence, well-implemented specialty probation appears effective in reducing general recidivism. Reform efforts for people with mental illness could leverage probation—a ubiquitous and revitalized node of the justice system.