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What Works and What Doesn’t in Pretrial Supervision?

New research summaries by Advancing Pretrial Policy and Research show that many practices aren’t backed by strong evidence.

Aitor Diago / GettyImages
Aitor Diago / GettyImages

How do you ensure that someone shows up to trial after they’ve been charged with a crime? For too long, the only answer offered by courts was to lock people up in jail. However, over the past several years, counties and states have been rethinking their pretrial policies and practices. In addition to moving away from cash bail and releasing more people before trial, courts are also working to find alternative policies that can increase appearance rates and reduce incidences of rearrest before trial. 

Advancing Pretrial Policy and Research (APPR) recently published a series of research summaries documenting key findings about pretrial policies and procedures implemented with the goal of maximizing community well-being and safety while reducing failure-to-appear rates. The results help show what works and what doesn’t as the nation’s judges, prosecutors, defense attorneys and advocates continue to reimagine a criminal justice system that considers the health and safety of everyone involved.

Pretrial Monitoring

Pretrial monitoring, also called pretrial supervision, is the process of maintaining contact with people to help them follow the court-ordered conditions of release. The specifics of what this looks like can vary broadly between jurisdictions, or even case to case. Systems can differ depending on the department responsible for overseeing operations, the method and frequency of maintaining contact, and the location of in-person contact. The lack of consistent practices makes it difficult to draw conclusions, and a lack of rigorous research makes it difficult to determine the effectiveness of specific practices. And often pretrial monitoring works to increase already-high rates of compliance — most people don’t need extra help to show up to court on time and avoid new charges pretrial. Nevertheless, researchers have come to several key findings about how pretrial monitoring can improve court appearance rates for people who need help the most. 

#1 Pretrial Monitoring Can Improve Court Appearance

    Compared to people who had no pretrial monitoring, people with pretrial monitoring had higher court appearance rates. Studies have found that pretrial monitoring can improve appearance rates by 2 to 24 percent. For example, researchers found that people being monitored in Orange County, California, appeared at a rate of 67 percent, while those not being monitored appeared at a rate of 54 percent. 

    #2 Pretrial Monitoring Does Not Appear to Reduce Pretrial Arrests

      While contact before trial can help people avoid missing court dates, the evidence does not show that monitoring alone decreases new arrests among people who are not detained before trial. A study of 3,200 people in Philadelphia found that, after controlling for key conditions, monitored and unmonitored people alike remained arrest-free 87 percent of the time.

      #3 Pretrial Monitoring Works Best with People Assessed as Least Likely to Succeed

        Researchers found that people who are already likely to appear in court don’t receive much benefit from pretrial monitoring. However, people who are less likely to succeed pretrial — as determined by a statistically validated assessment tool — receive a measurable benefit from monitoring. One study found that the appearance rate for people assessed as less likely to succeed pretrial climbed from 80 percent to 90 percent when they were part of a monitoring program. 

        #4 There Is a Lack of Research on Common Pretrial Monitoring Conditions and Practices

          Policies such as no contact orders, curfews, and driving interlock devices are routinely part of pretrial monitoring, but there is no empirical evidence of their impact on a person’s likelihood of appearing in court or remaining arrest-free pretrial. Nor is there research on how pretrial services agencies’ rewards and punishments for compliance and noncompliance affects rates of court appearance and pretrial arrest.

          Pretrial Location Monitoring

          The concept of the ankle monitor” has become shorthand for location monitoring — using an electronic device to ensure someone’s compliance with geographical conditions of release. While this has been studied in the context of probation or parole, less research exists about using location monitoring pretrial. However, the research that does exist finds little evidence that it leads to improved outcomes, and in fact can work to keep people unnecessarily entangled with the criminal justice system. 

          #1 There Is No Clear Association Between Location Monitoring and Improved Pretrial Outcomes

            Research remains inconclusive about the effects of location monitoring. Studies have found that people on location monitoring are more, less, or equally likely to appear for court or avoid pretrial arrest. This diversity of findings shows that more rigorous research is needed. 

            #2 Any Improvements as a Result of Location Monitoring Are Small

              Whether or not they’re subjected to location monitoring, most people successfully appear for their court dates and don’t have new arrests before trial. In fact, a New Jersey study put those statistics at 90 percent or more. With compliance already high, the value of location monitoring might not be worth the cost and labor required for implementation.

              #3 Location Monitoring Results in Increased Technical Violations

                While it is unclear whether location monitoring has a positive effect on rates of court appearance or avoiding pretrial arrest, the research overwhelmingly shows that it does result in higher rates of technical violations” — people breaking court-imposed pretrial conditions. One Illinois study found that more than 80 percent of technical violations were attributed to people on location monitoring. Most of those violations were related to the location monitoring itself, such as unauthorized absences or tampering with equipment. Researchers in a California study raised the possibility that location monitoring unnecessarily draws people into the justice system and that people can be effectively supervised in their communities under less restrictive conditions. 

                #4 Location Monitoring Can Lead to Poorer Pretrial Outcomes Among People Assessed as Most Likely to Succeed

                  A national pretrial study found that people statistically likely to succeed on pretrial release are twice as likely to fail when location monitoring is made a condition of release. This conclusion points to the principle that intervention resources should be prioritized for people who actually need help succeeding pretrial. 

                  #5 Research Is Mixed Regarding the Use of GPS Monitoring in Domestic Violence Cases

                    Research on GPS monitoring for domestic violence cases has come to mixed results and is largely inconclusive. In one study looking at domestic violence cases in the Midwest, GPS monitoring was associated with a significantly lower likelihood of arrest for another domestic violence offense. However, research looking at cases in the South found no statistically significant impacts from GPS. Researchers also found that people accused of domestic violence said they saw advantages and disadvantages with the conditions of GPS monitoring, bristling that the limits it imposed on their lives but also appreciating how it protected them from false claims. In the end, the study’s authors concluded that GPS monitoring should only be used when serving a specific purpose and that the due process concerns of the accused must be respected. A more recent study has found no evidence that GPS monitoring is associated with reductions in arrest for domestic violence cases. 

                    Pretrial Drug Testing

                    An escalation in the War on Drugs and new technology in the 1990s combined to make drug testing a routine part of pretrial conditions. By 2009, 77 percent of pretrial programs included drug testing of some kind. Despite this widespread use, there is little evidence that drug testing results in improved pretrial outcomes and in fact can lead to worse outcomes for people otherwise likely to succeed. 

                    #1 There Is No Clear Association Between Drug Testing and Improved Pretrial Outcomes

                      Randomized controlled studies in Arizona found inconsistent results on whether drug testing had an impact on people’s likelihood to miss a court date or be arrested before trial. A national study of people released pretrial found drug testing had no impact on people among people assessed as statistically less likely to succeed pretrial. However, specific processes vary among pretrial drug testing programs and more rigorous research is still needed. 

                      #2 The Impact of Noncompliance with Drug Testing on the Likelihood of Pretrial Failure Is Uncertain

                        Studies have mixed results, but recent research suggests that failing a drug test is not necessarily an indicator that someone is likely to be arrested before trial or miss a court date. In fact, one North Carolina study found that people who tested positive for drugs at least once during pretrial release had a higher success rate (71%) than people who never tested positive (67%). Given inconsistent results, drug testing doesn’t seem to be an effective strategy for improving pretrial outcomes. 

                        #3 Cost – Benefit Considerations Must Be Made

                          Drug testing is expensive. For example, in Pima County, Ariz., a new pretrial services drug testing program resulted in a 233% increase in staff workload that cost $311,000 over a 21-month period. Without a lack of strong evidence showing that drug testing improves pretrial outcomes, these costs can be difficult to justify. 

                          #4 Drug Testing Can Lead to Poorer Pretrial Outcomes Among People Assessed as More Likely to Succeed

                            A national study found that people assessed as more likely to succeed pretrial are significantly more likely to miss a court date or be arrested pretrial if release conditions include drug testing. Again, intervention resources should be focused on people who need help succeeding or otherwise efforts risk backfiring. 

                            Court Date Notification Systems

                            Failing to appear at a court date is considered a pretrial failure, but many of these failures are anything but malicious. People can miss a court date simply because they misunderstood court orders, forgot appointments, or faced routine obstacles such as work, childcare, or even traffic. Court date notification systems — which can rely on texts, phone calls, emails or letters to remind people of court times and locations — have a track record of increasing court appearance rates. However, effectiveness depends on the specific method and content of the notification.

                            #1 Court Notifications Can Increase Appearance Rates

                              A majority of studies have found that any type of court reminder is effective in improving court appearance rates. While a few studies were inconclusive about the benefits of notifications, no study has found that they had negative impacts. 

                              #2 Notification Content Matters

                                Two studies in Nebraska and New York City found that notifications were more effective when they stated the consequences of missing a court date. The New York study also found that appearance rates improved when notifications included tips on how to plan ahead for a court date. 

                                #3 Live Contact Improves Outcomes

                                  Studies find that live, in-person phone calls directly with a court representative produce the largest increases in appearance rates. However, research also shows that simply calling and leaving a message also improves outcomes. A study in Jefferson County, Colo. found that the appearance rate rose from a baseline of 79% to 87% when a message was left on voicemail or with a responsible adult, and to 92% when a person was reached directly. 

                                  #4 Notifications Have Financial and Nonfinancial Benefits

                                    A missed court date can be expensive for the criminal justice system. Issuing and clearing warrants, police apprehensions, jail bookings and bed stays, and court hearings all extract a cost. Court notifications can help the criminal justice system avoid those costs. Multnomah County, Oregon, saved more than $232,000 over six months by implementing court date notifications. Notifications also help people avoid unnecessary arrests and detention, and helps to build a fairer system by giving people the opportunity to speak with the court and receive helpful information.