Enhancing Procedural Justness of Encounters Through Substantiation (EPJETS): The Atlantic County Randomized Controlled Trial, New Jersey, 2022-2024 (ICPSR 39659)

Version Date: Mar 11, 2026

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Principal Investigator(s):
Nusret M. Sahin, Rutgers University. School of Criminal Justice; Joel M. Caplan, Rutgers University. School of Criminal Justice; Rob Voigt, University of California-Davis; Manish Madan, Stockton University

https://doi.org/10.3886/ICPSR39659.v1

Version V1

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Alternate Title

EPJETS

Summary

The Enhancing Procedural Justness of Encounters Through Substantiation (EPJETS) project was a collaborative initiative between researchers from Stockton, Rutgers, and Northwestern Universities and the police departments of Atlantic City and Pleasantville, New Jersey that aimed to test whether incorporating principles of procedural justice, sharing body-worn camera (BWC) footage with drivers following traffic stops, and strategically targeting identified high-traffic crash locations for enforcement could improve public trust and perceptions of police legitimacy. Between October 2022 and June 2024, the study evaluated 1,423 traffic stops conducted for speeding violations by comparing standard enforcement protocols to a novel procedural justice-based intervention. Drivers who were speeding were surveyed immediately after the stop by researchers to determine whether the EPJETS protocol positively affected their perceptions of officer treatment and the effectiveness of BWCs.

Citation

Sahin, Nusret M., Caplan, Joel M., Voigt, Rob, and Madan, Manish. Enhancing Procedural Justness of Encounters Through Substantiation (EPJETS): The Atlantic County Randomized Controlled Trial, New Jersey, 2022-2024. Inter-university Consortium for Political and Social Research [distributor], 2026-03-11. https://doi.org/10.3886/ICPSR39659.v1

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Funding

United States Department of Justice. Office of Justice Programs. National Institute of Justice (15PNIJ-21-GG-02718-RESS)

Subject Terms

Geographic Coverage

Smallest Geographic Unit

Geocoded street location

Restrictions

Access to these data is restricted. Users interested in obtaining these data must complete a Restricted Data Use Agreement, specify the reason for the request, and obtain IRB approval or notice of exemption for their research.

Distributor(s)

Inter-university Consortium for Political and Social Research
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Time Period(s)

2022 -- 2024

Date of Collection

2022-10 -- 2024-06

Data Collection Notes

  1. To measure officer adherence to the scripted procedure, the research team utilized natural language processing (NLP) analysis on transcripts generated from automatic speech recognition of the body-worn camera (BWC) footage from the traffic stops. The transcripts and footage are not available with this collection, but the Python code for transcript NLP analysis is included in the zipped package available with approved restricted access, and the BWC footage can be requested from the two collaborating police agencies. Please see the ICPSR README, Roadmap, and Whitepaper documentation files for more information.

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Study Purpose

The Enhancing Procedural Justness of Encounters Through Substantiation project was designed to evaluate whether a) utilizing procedural justice principles that emphasize fairness, dignity, neutrality, and transparency, b) using evidence-based targeted enforcement, and c) making body-worn camera footage accessible to citizens improve the quality of police encounters and enhances perceptions of law enforcement legitimacy.

Study Design

Officers from the Atlantic City Police Department (ACPD) and Pleasantville Police Department (PPD) conducted a total of 1,423 motor vehicle stops over 20 months. Drivers were randomly assigned to either a control group (n = 752), which experienced standard enforcement procedures, or an experimental group (n = 671), which was exposed to the Enhancing Procedural Justness of Encounters Through Substantiation (EPJETS) protocol that included the following elements:

  • A script emphasizing fairness, dignity, and transparency.
  • A pamphlet outlining high-risk accident zones, developed through risk-terrain modeling.
  • Participants were invited to complete an anonymous survey assessing their perception of the encounter.
  • Access to the body-worn camera (BWC) footage of their traffic stop, made available via a secure website.

The EPJETS script included two unique aspects: an explanation of how data-driven enforcement policies inform decisions and the accessibility of the BWC footage. Officers who were interested in taking part in the project received training from researchers that covered the basics of procedural justice and practice with using the EPJETS protocol and script. A total of 20 (13 from ACPD; 7 from PPD) officers were trained to deliver the project, and of these, 18 actively implemented the protocol.

At least one member of the research team was present to observe the traffic stops from a distance. Immediately after the official completion of the stop, the driver was invited to participate in a survey. If the individual agreed to participate, the officer would notify a research team member, who would then approach the driver to explain the purpose of the research and invite them to complete a 34-item questionnaire. The survey was available both on paper and via Qualtrics. A total of 753 drivers completed the survey, including 344 from the experimental group and 409 from the control group.

In order to ensure that the EPJETS script was closely followed, the research team reviewed BWC footage. Footage from each stop was uploaded to Evidence.com, an online police record storage system, which was also used to generate automatic speech recognition transcripts for each video. These transcripts and their associated metadata were pulled from Evidence.com for natural language processing (NLP) analysis. The NLP analysis dataset included 1,078 transcripts, 580 of which were from experimental stops and 498 were from control stops.

Sample

The study used random sampling. Randomization was achieved through white and colored index cards, which were shuffled and given to the officers who conducted the stops. The officer who pulled over the driver was required to draw a card from a stack of index cards each time they pulled over a driver for speeding. The card determined the specific protocol to be delivered.

Time Method

Cross-sectional

Universe

Drivers stopped for speeding in Atlantic County, New Jersey.

Unit(s) of Observation

Individual, Event/Process (Interactions with drivers)

Data Type(s)

Mode of Data Collection

Description of Variables

The dataset includes survey responses collected from drivers who were stopped for speeding and randomly assigned to receive the experimental protocol or a business-as-usual traffic stop. Respondents were surveyed on their perceptions of officer treatment during the traffic stop and general opinions on policing in the United States. Driver demographic information was also collected, including age, gender, race/ethnicity, education, income, and zip code.

The collection also includes a Traffic Stop Dates Excel file that documents traffic stop count totals and counts per date, time, agency, and experimental condition. Please see the ICPSR README documentation for more information.

Response Rates

The overall survey response rate was 54.95 percent.

Presence of Common Scales

To measure driver perceptions, a 5-point Likert scale (1 = Strongly Disagree, 5 = Strongly Agree) was used.

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Original Release Date

2026-03-11

Version History

2026-03-11 ICPSR data undergo a confidentiality review and are altered when necessary to limit the risk of disclosure. ICPSR also routinely creates ready-to-go data files along with setups in the major statistical software formats as well as standard codebooks to accompany the data. In addition to these procedures, ICPSR performed the following processing steps for this data collection:

  • Checked for undocumented or out-of-range codes.

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Notes

  • The public-use data files in this collection are available for access by the general public. Access does not require affiliation with an ICPSR member institution.

  • ICPSR usually offers files in multiple formats for researchers to be able to access data and documentation in formats that work well within their needs. If you have questions about the accessibility of materials distributed by ICPSR or require further assistance, please visit ICPSR’s Accessibility Center.

  • One or more files in this data collection have special restrictions. Restricted data files are not available for direct download from the website; click on the Restricted Data button to learn more.