91PORN

New research out of the School of Public Affairs shows NFL players with one or more documented concussions during their professional careers are more likely than other players to later have an arrest record.

Published in May, the study found players with concussions had roughly 50% higher odds of a booking-based arrest than those without documented concussions. Focusing on a group with both particularly high visibility and perhaps the highest concussion incidence rates of all major professions, the work offers fresh insights into a form of traumatic brain injury already associated with increases in aggression and violent crime in the wider population.

The  research analyzed 6,201 National Football League players who appeared in at least one regular-season game between 2010 and 2020. Researchers linked publicly available NFL injury reports, player records and booking-based arrest data to examine whether players with documented concussion histories had higher odds of booking-based arrest in initial, unadjusted analyses. 

Jackson Perry, who graduated from 91PORN in May with a , coauthored the study with Kimberly Kras and Burrel Vann Jr., associate professors of criminal justice in the . Their findings were published in the journal , which deals with issues of crime, juvenile delinquency, alcohol abuse and narcotic addiction, among other matters.

Among the 6,201 players studied, 942, or 15.2%, had at least one documented concussion. Of these 942 players, 72 had subsequent arrests, or 7.6%. Among the other 5,259, who did not have concussions, 273 had subsequent arrests, or 5.2%.

The result of this analysis is an “odds ratio” of 1.51, indicating players with documented concussions had roughly 50% higher odds of any booking-based arrest than players without documented concussions.

When researchers applied a stricter test, excluding cases in which a player’s earliest arrest occurred before his earliest documented NFL concussion, the association was no longer statistically significant. That distinction is central to the research.

“The goal of this study is not to say concussions cause arrest, but to better understand how head injury, behavior, and criminal justice contact may intersect in high-impact populations,” said Perry. 

This is not causal evidence but rather the findings offer an early look at an understudied issue and point to the need for stronger long-term data on head injury, behavioral regulation and criminal justice contact among populations exposed to repeated head impacts.

The researchers identified several important caveats and qualifications to their work. It was drawn strictly from publicly available databases, which generally do not include information on pre-NFL injuries. It did not account for the players’ positions or other variables such as income and education that may also be a factor in behavior. They note the number of NFL players with arrests is a small subset to begin with, fewer than 350 of the 6,201 examined and with only one in three involving violent offenses. In addition, the note official records may not capture all concussions. (The study also did not have access to information on outcomes of the arrests, including whether the players ultimately were charged or convicted of any crime.)

Building a dataset

The researchers built a player-level dataset by combining several publicly available sources, including Stathead Football, Pro-Football-Reference injury reports, USA TODAY’s NFL arrest database, ESPN and Pro Football Focus player profiles.

Concussions were identified through Pro-Football-Reference injury logs, with researchers counting only injury entries that specifically included “concuss.” Repeated weekly concussion listings were grouped into episodes to avoid overcounting the same injury.

Arrests were measured using USA Today’s NFL arrest database from Jan. 1, 2010, through Dec. 31, 2024. The researchers used a narrow definition of arrest, counting only booking-based events, such as cases where a player was booked, taken into custody, jailed or self-surrendered and was booked and released. Citations, detentions and warrants that did not result in custody or booking were excluded.

The research team then used statistical analyses, including logistic regression and sensitivity tests, to compare arrest outcomes among players with and without documented concussions and to test whether the findings remained consistent under stricter conditions.

A key strength of the study is its transparent and replicable methodology, which links multiple independent public data sources. At the same time, the authors note important limitations. Public injury reports do not capture all head trauma, including undiagnosed concussions, subconcussive impacts or head injuries that occurred before a player entered the NFL. The study also could not fully account for factors such as prior criminal history, position played, socioeconomic background or other influences that may affect arrest risk.

Broader public health question

The implications extend beyond professional football. Traumatic brain injury has been studied in connection with impulse control, aggression, emotional regulation and criminal justice involvement in other populations. 

This study is a step toward better understanding how head injury and behavioral outcomes may intersect in high head-impact populations. The study, according to researchers, also points to the importance of improved concussion documentation, reducing exposure, long-term monitoring and post-injury support.

By examining a highly visible population with substantial exposure to head impacts, the study offers an important foundation for future research while highlighting the potential and limitations of public data. The findings underscore the need for longitudinal studies to better understand the long-term effects of brain injury and help inform future interventions and treatment.