NIJ’s Multisite Evaluation of Prosecutor‑Led Diversion Programs: Strategies, Impacts, and Cost‑Effectiveness

Executive Summary

In recent years, a growing number of prosecutors have established pretrial diversion programs, either pre-filing—before charges are filed with the court—or post-filing—after the court process begins but before a disposition. Participating defendants must complete assigned treatment, services, or other diversion requirements. If they do, the charges are typically dismissed. With funding from the National Institute of Justice, the current study examined 16 prosecutor-led diversion programs in 11 jurisdictions across the country and conducted impact evaluations of five programs and cost evaluations of four programs.

Overview of Study Design and Methods

The study design included separate process, impact, and cost evaluations. First, the purpose of the process evaluation was to provide a comprehensive portrait of prosecutor-led diversion programs as it exists today. We sought well-established, high-volume programs in order to investigate how these programs operate when they “go to scale.” We used a standard set of process methods, including document review, direct program observations, and in-depth stakeholder and staff interviews. The interviews relied on a 31-page, 103-question interview protocol covering program history, the current model, strengths and challenges, and available data. We also conducted participant focus groups with participants in six of the programs.

Second, quasi-experimental impact evaluations were conducted on five programs in three sites (two programs each in Cook County, Illinois and Milwaukee, Wisconsin, and one in Chittenden County, Vermont). For each program, we matched diversion participants to comparison groups composed of similar but non-participating defendants. After matching was complete, we found that defendants in the diversion and comparison samples did not significantly vary on background demographic, charge, and criminal history characteristics.

Third, four programs in three sites (two programs in Cook County and one program each in Chittenden County and San Francisco, California) were included in a cost study that estimated the investment costs resulting from time spent by prosecutors, public defenders, and court staff on diversion versus similar comparison cases. The analysis also examined output costs including, for example, the costs of probation, jail, or prison sentences that might be differentially imposed on diversion and comparison cases.

Goals of Prosecutor-Led Diversion

• Multiple Goals: Diversion programs of the 1970s tended to prioritize defendant rehabilitation and recidivism reduction. Today, these goals occupy a less preeminent role. The most commonly endorsed goals were: (1) administrative efficiency and cost savings (by routing cases away from traditional prosecution and directing resources to other more serious cases); and (2) reducing convictions and collateral consequences for defendants.

Target Populations

• Timing of Diversion Participation: Of 15 programs in the study, eight were post-filing, three were pre-filing, and four programs enrolled participants either prior to or after filing charges with the court depending on case specifics (mixed model).

• Misdemeanors and Felonies: Unlike programs of the 1970s, current models are not exclusively focused on the lowest level cases. Instead, nine of 15 programs we examined either targeted felonies or a mix of misdemeanors and felonies.

• Specialist Programs: Six of 15 programs targeted specific types of crimes, most often drug or marijuana possession, although one program in Hennepin County, Minnesota targeted both felony-level drug and property cases and another program in Phoenix, Arizona targeted misdemeanor prostitution cases.

• Risk-Informed Decision-Making: The programs we examined generally made eligibility determinations based on charge and criminal history, not validated risk assessments. A notable exception was in Milwaukee, which adopted a universal risk-informed screening protocol, leading low-risk defendants to be routed to a brief, pre-filing program and medium-risk defendants to be routed to a more intensive post filing program, with services tailored to each defendant’s needs.

Program Mandates

• Standardized vs. Individualized: Of 15 programs examined, five use a “one size fits-all” approach, whereas ten programs use individualized mandates to some degree, assigning different types of services based on defendants’ needs.

• Educational vs. Therapeutic Models: Thirteen of the 15 programs link at least some participants to educational classes about the relevant problem behavior, including classes about drugs, driving, theft, prostitution, weapons, health, and/or parenting. Staff at only one program cited the consistent use of evidence-based cognitive-behavioral approaches, although two additional programs use these approaches with some cases.

Community Restoration: Ten of the 15 programs order at least some participants to perform community service. In addition, four programs use restorative justice groups with at least some participants. Restorative justice, in which defendants accept responsibility and repair the harm caused by their actions and, in turn, are reintegrated into the community, represents a core organizing principle of the model for San Francisco’s Neighborhood Courts diversion program and Los Angeles’ newly created Neighborhood Justice Initiative.

Case Outcomes, Recidivism, and Cost

• Case Outcomes: All five programs participating in impact evaluations (two in Cook County, two in Milwaukee, and one in Chittenden County, VT) reduced the likelihood of conviction—often by a sizable magnitude. All five programs also reduced the likelihood of a jail sentence (significant in four and approaching significance in the fifth program).

• Re-Arrest: Four of five programs reduced the likelihood of re-arrest at two years from program enrollment (with at least one statistically significant finding for three programs and at least one finding approaching significance in the fourth). The fifth site did not change re-arrest outcomes.

• Cost: All four programs whose investment costs were examined (two in Cook County and one each in Chittenden and San Francisco) produced sizable cost and resource savings. Not surprisingly, savings were greatest in the two pre-filing programs examined, which do not entail any court processing for program completers. All three programs whose output costs were examined (i.e., omitting the San Francisco site) also produced output savings, mainly stemming from less use of probation and jail sentences.

Conclusions

There were a number of important study limitations, including a focus on 16 high-volume diversion programs mainly located in large jurisdictions, a smaller number of study sites for the impact and cost evaluations, and limitations in the scope and quality of quantitative data available in some of the impact sites. Understanding these limitations, we generally found that today’s prosecutor-led diversion programs pursue a wide range of goals, not limited to rehabilitation and recidivism reduction. We also found that these programs serve a mix of target populations—including felonies as well as misdemeanors and, in virtually all programs we examined, including defendants with a prior criminal record. Although it bears noting that we evaluated program impacts in a limited number of sites, meaning that our findings may not be generalizable to other sites and programs that we did not study, our research yielded positive results. Across five programs in three sites, diversion participants benefited from a reduced likelihood of conviction and incarceration; and in four of the five programs, pretrial diversion participation led to reduced re-arrest rates. In addition, in all four programs where a cost evaluation was conducted, diversion cases involved a lesser resource investment than similar comparison cases.