The growing amount of data available on the United States criminal justice system has made it much easier for researchers to gain deep insights into it. But the diverse community of practitioners advancing that work — including academics, public agencies, journalists, lawyers, and computer scientists — often operate in siloes that limit awareness, lead to inefficiencies in effort, and reduce the potential impact of such insights.

To help break those siloes down, the Criminal Justice Initiative at the Princeton School of Public and International Affairs convened an open data summit in August, supported by funding from Arnold Ventures, for national criminal justice leaders to come together and discuss ways to increase transparency and usability of criminal justice data. The Initiative has now released a report summarizing the event and key recommendations.

“We have more data than ever on the workings of the criminal justice system, but it remains challenging to clean, synthesize, and use in ways that account for deficiencies and biases,” said Jonathan Mummolo, associate professor of politics and public affairs at Princeton SPIA and a co-organizer of the event. “We stand to learn an immense amount, but only if these new information sources are used efficiently and carefully. This event was an effort to bring together a range of people working to gather and disseminate these data in order to streamline and improve these efforts.”

During the day, attendees heard from four panels of speakers, each followed by a question-and-answer session, and participated in roundtables and discussions on how the decentralized nature of criminal justice data in the U.S. leads to challenges such as uneven data quality.

“The technical ability to produce reliable, timely, and well-documented data now exists,” the report states. “The question is how to sustain it, coordinate it, and ensure it is used responsibly.”

Participants agreed that while progress is accelerating, structural issues remain. Data can be limited, fragmented, inaccurate, and poorly maintained. Yet the overall trajectory is positive, they added.

The summit highlighted innovative projects like the Real-Time Crime Index, the Jail Data Initiative, and the Civic Police Data Project, which demonstrate that compiling near-real-time, publicly accessible data is possible.

Still, participants stressed that technical innovation must be paired with transparency and ethical responsibility. Without context, even well-intentioned users can misinterpret trends, such as mistaking reporting delays for crime spikes.

Dashboards and visualization tools were a point of discussion. 

“When information is presented in simple, visual form, users are less likely to consult the documentation,” the report notes. To address this, participants emphasized that designers must build dashboards carefully so users are not misled by simplified visuals or missing context.

The report outlines five priorities for advancing open criminal justice data:

1. Investing in long-term data infrastructure to maintain continuity and quality.
2. Establishing shared standards and documentation for easier data usage and linkage.
3. Improving academic incentives for data collection and sharing.
4. Expanding open-data initiatives beyond policing to include call-takers, dispatchers, courts and corrections.
5. Pursuing a “moonshot” project—a research-focused records management system to be used within law enforcement agencies that embeds data validation, documentation, and standardization at the point of entry.

The proposed records management system could transform the field by creating “good data at the source,” reducing costly downstream cleaning and improving usability for agencies and researchers alike. Such a system could also raise expectations across the industry, encouraging vendors to improve usability, accuracy, and transparency in the tools they provide to agencies.

“The aim of the summit was to bring together the people who build and maintain open criminal justice data so we could learn from one another and develop a concrete vision for what the field should pursue over the next few years,” said Jacob Kaplan, professional specialist at Princeton SPIA and a co-organizer of the summit. “Having everyone in the same room clarified the work ahead and led directly to several new projects that are already moving forward.”

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