Pretrial Nudges

Encouraging appearance in court using new techniques from reinforcement learning.

Pretrial Nudges logo

Criminal courts often take months or years to adjudicate a case. Meanwhile, many legally innocent defendants awaiting trial are held in jail to ensure they appear in court. But this pretrial detention is harmful to individuals and communities.

As an alternative, courts can also choose to release individuals into the community. But these “free” defendants are required to appear at mandatory criminal court hearings every few weeks. This task is a tremendous burden for poor and under-resourced individuals who are disproportionately impacted by the criminal legal system. When people accused of a crime fail to appear at their mandatory court hearings—usually because they lack transportation, childcare, a calendar, or medication for mental illness—courts can impose severe consequences. A missed court date usually results in an arrest warrant and automatic incarceration during the individual’s next encounter with courts or law enforcement.

Fortunately, it’s possible to cheaply and substantially improve court appearance rates by sending court date reminders to individuals. In partnership with The Bail Project and Santa Clara County Office of the Public Defender, we are building a mobile phone application that will help advocates seamlessly communicate with their clients and automatically send text court reminder messages to individuals with pending court dates. Additionally, we are leveraging modern methods from reinforcement learning to personalize the content and timing of court date reminders, choosing a reminder strategy that is most effective for each recipient. We will also use reinforcement learning to identify individuals most likely to benefit from transportation assistance and will provide them with a free ride to court through a rideshare service.

Our aim is to improve appearance rates and the terrible collateral consequences of missing court. If it works, judges may be less concerned about defendants missing their mandatory court hearings and may reduce the number of legally innocent people held before their trials.

Once we have successfully prototyped this platform, we will release the software as a free and open-source tool so that other cities and counties can use these tools to reduce pretrial incarceration in their own jurisdiction.


Sophie Allen


Alex Chohlas-Wood

Faculty Co-Director

Madison Coots


Sharad Goel

Faculty Co-Director

Amelia Goodman


Daniel Jenson


Joe Nudell

Lead Engineer

Julian Nyarko