What Effect is the PFA having on Pretrial Jail Usage?

Not now, but soon—maybe as soon as next month—we’ll be in a position to provide at least a preliminary answer to one of the big questions surrounding the PFA: how is it impacting jail populations?

Working with the Administrative Office of the Illinois Courts and the Illinois Department of Corrections’ Jail and Detention Standards Unit, we’ve begun to assemble the first-ever public data dashboard tracking pretrial jail bookings and length of pretrial detention in each of Illinois’ 92 county jails, as well as the number of individuals on pretrial supervision in each county. The dashboard will be updated every month, and will include historic information going back at least to 2018, enabling users to see how pretrial custody and pretrial supervision numbers have changed over time, and how they are changing with the implementation of the PFA.

In the meantime, post-PFA jail population data from a handful of counties for which daily information is readily available suggest that the new law is reducing jail detention, but the magnitude of change varies across counties. This variation in jail population changes likely reflects differences in (1) how counties use their jails and/or (2) how counties may have begun changing their pretrial detention practices before the effective date of the PFA. For example, some jails may hold a larger share of individuals who are sentenced to jail rather than held pretrial, which would result in the PFA’s having less of an impact on the total jail population. Similarly, some but not all counties may have begun to change their pretrial detention practices, and particularly their use of cash bonds, well before the effective date of the law.