Electronic monitoring, or what is commonly called “tether” in Wayne County, is widely used pretrial, but there is not compelling evidence that it increases public safety.There is limited research on pretrial electronic monitoring generally, and the research that does exist is often methodologically flawed, equivocal, or limited to specific populations like people charged with domestic violence or sex offenses. A number of meta-analyses and literature reviews have concluded that there is not enough evidence to support the effectiveness of electronic monitoring, with some studies even showing an increase in pretrial failure for those on electronic monitoring. See for example Marc Renzema and Evan Mayo-Wilson, "Can Electronic Monitoring Reduce Crime for Moderate to High-Risk Offenders?" Journal of Experimental Criminology 1, no. 2 (2005), 215-237; Marie VanNostrand, Kenneth Rose, and Kimberly Weibrecht, State of the Science of Pretrial Release Recommendations and Supervision (Rockville, MD: Pretrial Justice Institute, 2011), https://perma.cc/B8YF-G39E; Jyoti Belur, Amy Thornton, Lisa Tompson et al., A Systematic Review of the Effectiveness of the Electronic Monitoring of Offenders (London: What Works Centre for Crime Reduction, 2017), https://perma.cc/K6LH-3R6F; and Karla Dhungana Sainju, Stephanie Fahy, Katherine Baggaley et al., "Electronic Monitoring for Pretrial Release: Assessing the Impact," Federal Probation 82, no. 3 (2018), 3-10, https://perma.cc/B22G-59A3. Two recent studies did find some benefit from pretrial electronic monitoring, but their results were contradictory. One study of federal pretrial defendants in New Jersey found that electronic monitoring reduced rearrests but had no effect on failure to appear, while the other study, of state pretrial defendants in Santa Clara County, California, found that electronic monitoring reduced failure to appear but slightly increased rearrests. See Kevin T. Wolff, Christine A. Dozier, Jonathan P. Muller et al., "The Impact of Location Monitoring among U.S. Pretrial Defendants in the District of New Jersey," Federal Probation 81, no. 3 (2017), 8-14; and Sainju, Fahy, Baggaley et al., "Electronic Monitoring for Pretrial Release: Assessing the Impact," 2018. It is also worth noting that pretrial success rates in both studies were very high for all defendants, regardless of whether they were electronically monitored. A large number of people spend several months on such monitoring. According to Vera’s analysis of Wayne County Jail data, the longer people spend under electronic monitoring, the more likely they are to violate its rules and return to jail. While the electronic monitoring program in Wayne County has effectively reduced the jail population, it comes at a cost: people assigned to monitoring pretrial pay fees of $100 for enrollment and $100 per month, which can cause them to incur significant debt paying for the cost of monitoring regardless of whether any unpaid fees result in reincarceration.

Key Findings

  • Electronic monitoring is primarily used pretrial, with 71 percent of the average daily population under electronic supervision legally innocent.


  • Many of those people under electronic supervision pretrial have been charged with misdemeanors or lower-level felonies.


  • Sixty-three percent of people released to electronic monitoring pretrial in Wayne County had a monetary bond set in addition to being assigned to monitoring.
  • While the average amount of time spent under electronic monitoring was 58 days, a large number of people are monitored for between two and six months.

Reduce the use of pretrial electronic monitoring and improve its administration in cases where it is used.

Wayne County should take steps to reduce the use of electronic monitoring pretrial, as many people can be safely managed in the community without such restrictions. If electronic monitoring is going to be used, Wayne County should limit its use to cases where there is a specific justification for monitoring that relates to an individualized assessment of a person’s pretrial risk of reoffending. Even in cases where monitoring is considered necessary and a device is assigned, there are several ways Wayne County can improve its administration, such as by:

  • assuring that conditions are the least restrictive possible to address the specific reason for ordering the monitoring;
  • expediting a person’s release from jail when electronic monitoring is assigned;
  • limiting the amount of time people remain on electronic supervision;
  • ordering release on personal recognizance, eliminating the practice of both assigning a monitor and setting a cash bond; and
  • reducing the financial burden of electronic monitoring by eliminating user fees.