Missing traffic stop data from Pa. State Police undercut 2021 analysis for racial disparities

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More than 85% of Pennsylvania State Police stations failed to collect demographic data for all traffic stops last year after an agency-wide pledge to resume the practice, leading researchers to conclude it was impossible to analyze for potential disparities.

State Police announced the renewed effort after Spotlight PA revealed the department had stopped collecting the information without explanation or public notice in 2012, making it an outlier among statewide police agencies.

Without such demographic data, it’s nearly impossible to detect racial bias in State Police practices.

In response to the investigation, the department contracted with researchers at the University of Cincinnati Center for Police Research and Policy to analyze the data and look for any patterns of racial disparities.

The researchers initially planned to release an analysis in April, but in a report published this month, they said they found discrepancies that raised “serious concerns regarding the validity of the 2021 data,” and rendered any substantive analysis “not possible.”

State Police worked with a team led by Robin Engel, a criminologist and former director of the Center for Police Research and Policy, to develop a form each trooper is required to fill out after making a traffic stop.

The form requests details on the circumstances surrounding the stop, such as time of day and place; the demographics of the driver; the outcome of the stop; and trooper-identifying information such as assigned station and demographics.

Throughout 2021, State Police added to and updated the form to capture additional information and to reduce the chance of error.

But troopers in some stations did not realize they had to complete the form for stops that resulted in only a verbal warning, Engel told Spotlight PA.

“We recognized that that was an issue probably midway through the year, that some stations had … been misinformed,” she said. “They just literally didn’t know that they had to complete the [form] if the only action was a verbal warning.”

While auditing the data, the researchers compared the number of completed forms to the number of recorded traffic stops to determine if any were missing. They found hundreds.

Fifteen stations, as well as the State Police canine unit, failed to collect data on 20% or more of all stops made last year. This includes the State Police post in Highspire, the headquarters of the department’s turnpike patrol, which did not record information for any of the 205 stops its troopers made last year.

Overall, State Police troopers failed to complete forms for more than 12% of the stops they made, a greater error rate than industry experts recommend for sound data analysis, the researchers wrote.

Without information on those stops, the researchers said they cannot make any conclusions about racial disparities.

“For example, it could be that verbal warnings are more likely to be issued to a particular racial or ethnic group than others,” Engel said. If some verbal warnings are missing from the data, then any conclusions about race could be wrong. “We don’t know that, but that’s a real concern.”

The department sent revised guidance to troopers reinforcing that verbal warnings must be recorded, and the data collection form has since been updated to include “verbal warning” as a possible outcome of a stop.

Engel said she expected data collection issues the first year of the renewed program, but found that State Police were receptive and made the fixes necessary to correct the issue.

State Police did not have further comment on the report.

The department released two additional reports this month summarizing data collected in 2022, but will not conduct any analysis until the end of the year. The researchers will provide an annual report detailing any findings, including whether the data show any racial disparities, on March 31, 2023.

The researchers will work with State Police through 2025 and plan to provide annual reports to the department for the next three years. The four-year contract will cost State Police $696,000, including $174,000 already paid out for work completed in 2021.

This is the second time State Police have partnered with Engel to examine traffic stop data for evidence of racial disparities. Officials initially told Spotlight PA they stopped collecting the data because the analysis, which spanned 2002 to 2010, showed no evidence that troopers conducted traffic stops based on race or ethnicity.

While Spotlight PA’s review confirmed that researchers did not find evidence that state troopers stopped Black and Hispanic people at a disproportionate rate, the analysts did find that once pulled over, troopers subjected people of color to citations, arrests, and searches more often than white people.

And despite initiating fewer searches of white drivers, the researchers noted police more often found contraband in their cars than in the cars of Black and Hispanic drivers.

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