Incorporating Data and Evidence Into Criminal Justice Policy Decisions: Options and Resources



Criminal justice reform efforts are underway across the country, and good data is key to their success.

Legislatures are examining every part of the system, seeking to improve pretrial practices, refine sentencing laws and align corrections and supervision practices with evidence-based principles. Using data, lawmakers are learning more about factors driving people’s involvement in the criminal justice system, population trends and operational costs.

Despite the momentum of reform efforts and the appetite for data, state legislators face a variety of challenges that hinder access to, and effective use of, data.

This page highlights state actions to incorporate data and evidence into criminal justice policies. It also features relevant resources from NCSL and the Justice Counts initiative, a Bureau of Justice Assistance project designed to help policymakers make better decisions with criminal justice data that is more timely, less disjointed and as useful as possible. The initiative is led by The Council of State Governments Justice Center in partnership with NCSL and other national organizations.

Overview: How Data and Evidence Can Inform Budget and Policy Decisions

State leaders make policy and budget decisions in areas such as public safety, health and well-being and educational attainment that directly affect their residents. Policymakers in many states look to the best available research and data to guide their decisions and ensure the greatest impact.

An evidence and data-informed approach can help officials from all branches of government strategically invest resources in effective programs and policies, encourage innovation, improve transparency in budgeting and build and sustain a culture of continuous learning and improvement.

Data-driven policymaking can help stakeholders across government allocate resources to programs that are effective, promote innovation and build and sustain a culture of improvement. Having quality, timely data enables conversations to identify root causes of problems and develop evidence-based solutions.

See NCSL’s 2020 issue brief, “The ABCs of Evidence-Informed Policymaking,” for additional detail about how states are using evidence to guide policy and budget decisions.

Incorporating Data Into Criminal Justice Decisions: 4 State Options and Actions

Legislators are seeking data and resources that can help them realign their policies to focus dollars on the highest public safety return on investment. As described below, legislatures are adopting a wide range of strategies to support data-driven reforms, including developing capacity to collect and use data, engaging in partnerships, directing funds to criminal justice data initiatives and communicating data to inform policy decisions.

1. Develop data and performance measurement capacity. Several states have taken steps to increase the uniformity and comparability of criminal justice data. Colorado and Connecticut both enacted legislation in 2019 requiring that certain local data be collected.

For example, Colorado's law focused on jails and jail populations, and Connecticut's on prosecutorial decisions. These approaches reflect lawmakers’ interest in knowing whether specific policy changes are working. In 2022, Utah created a Criminal Justice Data Management Task Force that seeks to promote criminal justice data sharing, as well as examine ways in which the state can standardize and automate the collection of criminal justice data.

2. Engage stakeholders and partner with experts. These include partnerships within government, such as cross-branch collaboration between legislative and executive branch stakeholders, as well as external partnerships with researchers, funders and state policy resources and organizations.

Higher education institutions can lend students, professors, and other resources to analyze how accurately proposed reforms respond to what the data is showing. Clemson University’s Institute for Economic and Community Development, for example, performed an economic impact study on the first three years of South Carolina’s 2010 reform law.

Universities also can help set up data systems. The City University of New York’s Institute for State and Local Governance is working in 20 cities and counties that are part of the John D. and Catherine T. MacArthur Foundation's Safety and Justice Challenge. The institute has helped cities and towns create and track performance measures related to the goals of the foundation’s challenge, namely reducing jail populations and the disparities within them.

3. Fund programs, policies and practices that are seeing success and backed by research. Customized and real-time research resources including policy impact memos and timely, accessible data help leaders make informed budget and policy decisions that produce better outcomes and are a more efficient use of public resources.

For example, as part of their partnership with the Pew Results First Initiative, the Iowa Department of Corrections (DOC) inventoried current programs, collected data on the evidence of effectiveness and used research studies to categorize programs based on their likelihood of reducing recidivism. As a result, the DOC shifted resources to proven programs that support the department’s goals.

4. Display data in a way that can guide policy decisions. To reach its full potential, data must be communicated clearly, and research findings must be accessible and meaningful to policymakers and address key policy objectives.

To share the right information at the right time in the decision-making process, many states have taken steps to deliver data dashboards to communicate timely and actionable data.

For example, after the Oregon Legislative Assembly passed reforms in 2013, lawmakers wanted a way to monitor the changes and their effects on the system. The state’s Criminal Justice Commission created online dashboards to graphically display measurements such as prison populations, jail and community supervision populations, prison composition, crime and recidivism rates and corrections spending.

Similarly, in 2020, the Virginia Community Policing Act began requiring the collection of law enforcement stop data from across the state. That information is now housed and regularly updated on an online portal that provides visualizations of data related to investigatory stops, including demographic and geographic information.

About Justice Counts

Justice Counts includes 21 partner organizations representing the nation’s state, county and municipal justice systems. The initiative is led by the U.S. Department of Justice’s Bureau of Justice Assistance and The Council of State Governments Justice Center. Justice Counts is guided by a steering committee of active state and local officials—from law enforcement, to corrections, to legislatures and beyond.

Justice Counts maintains state-level data and a national corrections data dashboard, which summarizes prison, probation and post-release supervision population data as reported by states. With input from the national coalition of stakeholders, Justice Counts released its Tier 1 metrics, which measure costs, capacity, equity and other factors across seven sectors of the criminal justice system including law enforcement, defense, courts and prisons. Providing this type of standardized, real-time data can help policymakers measure trends and make comparisons across the justice system.

The initiative will also assist selected states directly through the Founding States and Implementation Grant Programs. Ten Founding States will receive intensive technical assistance related to adopting and sharing the criminal justice metrics. States can join the program through one of five paths, such as issuing an executive order or passing a legislative resolution, as described in this toolkit. The Implementation Program, which will provide grant funding to 15 states to adopt the metrics is overseen by the Bureau of Justice Assistance.

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NCSL Resources

Additional Legislative Resources

Additional Resources