Recent research published in journals deviant behavior This suggests that professional soccer players with a history of concussions are more likely to be arrested than those without such a history. These findings provide preliminary evidence that brain injuries sustained in high-impact sports may be associated with subsequent interactions with the criminal justice system.
Traumatic brain injury is a type of injury that affects the normal functioning of the brain. These injuries are often caused by a hard blow or impact to the head, or sudden acceleration or deceleration of the body. This rapid movement causes the brain to bounce and twist inside the skull, causing chemical changes that sometimes stretch and damage brain cells.
Medical professionals recognize that these physiological changes in the brain can increase the likelihood of certain behavioral problems. Specifically, damage to the frontal and temporal lobes of the brain, areas responsible for decision-making and emotion, tends to reduce impulse control and limit the ability to inhibit aggressive behavior.
Previous research linking brain injury to behavior has highlighted an increased risk of violent crime among those affected. Some people with brain injuries have difficulty regulating their emotions and controlling impulses. Impulsivity is characterized by a lack of planning and increased risk-taking behavior. This lack of self-regulation can, in some cases, result in behavior that violates the law and may lead to police being contacted.
High-influence sports populations provide an opportunity to investigate these associations in more detail. National Football League players have a disproportionately high incidence of head injuries compared to the general population. Cumulative damage from repeated head impacts can lead to conditions such as chronic traumatic encephalopathy. This progressive brain disease is associated with a history of repeated head injuries and is characterized by gradual shrinkage of the brain and enlargement of its fluid-filled spaces.
The authors of the new paper sought to clarify this relationship by examining whether officially recorded concussions affect the likelihood that a player will be formally reported to the police. “The motivation for this study came from the empirical gaps we saw in NFL criminology research,” said lead author Jackson Perry, a freshman doctoral student in criminal justice and criminology at Florida State University. He co-authored the paper with Kimberly Klass and Burrell Vann Jr., both professors at San Diego State University’s School of Public Affairs.
Perry has noticed that public conversations about concussions, brain diseases, and player arrests often take place in separate lanes. “Most research on NFL players in criminology and public health treats concussions and arrests as separate issues, even though both touch on player health, behavior, and long-term support,” Perry explained. “Public conversations about concussions, CTE, and player arrests in the NFL often take place in separate lanes, and when they overlap, they can quickly become speculative.”
He noted that these overlapping issues require formal research. “I wanted to bring a criminology perspective to this overlap and ask a direct empirical question: Among the available public data, are documented NFL concussions associated with booking-based arrest outcomes?” Perry noted. “The bigger issue for me is that brain health should also be considered, not just in the immediate aftermath of an injury, but also in player support during and after football.”
To investigate this topic, researchers constructed their own dataset using several publicly available sources. They focused on a large sample of 6,201 professional football players who appeared in at least one regular season game between 2010 and 2020. They collected weekly injury reports from a statistical database over the past 11 years and identified players with at least one officially recorded concussion.
A concussion is a mild traumatic brain injury that temporarily disrupts brain function. Because players can suffer multiple head injuries over the course of their careers, the researchers took steps to accurately measure individual injury events. They coded new concussion episodes only if they occurred more than 2 weeks after the onset of the previous injury, excluding bye weeks. This step helped balance the data and prevent overcounting a single injury that simply kept a player on the injury report for several weeks in a row.
As a key result, the scientists tracked booking-based arrests from January 2010 to December 2024. The researchers used the famous public arrest database maintained by USA TODAY, which tracks legal cases involving professional football players. The researchers specifically defined an arrest as an event in which a player is formally detained, jailed, or turned over to authorities for repossession. We excluded cases where the player was only issued a citation, was detained for a short period of time without formal booking, or where the warrant was revoked.
When an arrest case contained multiple charge descriptors, the researchers used a severity hierarchy to assign a single crime category. Violent crimes had the highest rates, followed by property crimes, public order crimes, and criminal justice-related crimes. This coding system allowed researchers to examine overall arrest trends and specific rates of violent arrests.
The researchers found that 942 athletes, about 15.2 percent of the study sample, recorded at least one concussion during the 11-year observation period. Arrests, on the other hand, were relatively rare overall. Only 345 players, representing 5.6% of the sample, experienced a booking-based arrest during the study period. Analyzing the statistical relationship between these two factors, the authors found that concussion exposure was associated with increased arrest rates.
“The effect was meaningful, but it needs to be interpreted in context,” Perry said of the statistical difference. “In the unadjusted model, the predicted probability of arrest was approximately 5.2% for athletes without a record of concussions and approximately 7.6% for athletes with a record of concussions, an absolute difference of approximately 2.5 percentage points. This difference is large enough to raise serious questions: Are we doing enough to understand and support athletes who have been repeatedly exposed to head impacts?”
The researchers also looked specifically at violent arrests as a secondary outcome. They noted a similar pattern in the raw numbers, with 2.3 percent of players with concussions facing violent arrests compared to 1.5 percent of players without concussions. However, this particular association with violent crime did not reach statistical significance. This means that the mathematical differences were not large enough to rule out random chance as the cause.
When researchers examined the timing of arrests and injuries, important nuances emerged. They conducted a secondary test that excluded cases where the player’s first arrest occurred before the first recorded occupational concussion, but the association was no longer statistically significant in this limited test. “What was most remarkable was how critical the timing was for the story,” Perry said.
“This association emerged in the primary unadjusted analysis and held when arrests were limited to the 2010-2020 observation period, but it did not hold under a more stringent test that excluded cases where the earliest arrest occurred before the earliest recorded NFL concussion,” Perry told SciPost. This sensitivity to temporal order suggests that childhood head trauma prior to joining a professional league may be influencing a broader pattern.
“That doesn’t make the issue any less important,” he says. “This shows why we need stronger life course data on this topic. Many players begin playing football years before the NFL, so the first recorded NFL concussion may only capture a small portion of a much longer history of head impact exposure.”
The authors offer several cautions against misinterpreting these results as direct causation. “The main misconception I want to avoid is the idea that this study proves that concussions cause arrests and violent behavior,” Perry warned. “That’s not the case. What we found was an association of observational data that documented NFL concussions capture only a portion of a player’s entire head impact history, and not all concussions, subconcussive contusions, pre-NFL injuries, injury severity, and recovery process.”
Despite these limitations, the findings highlight the need for continued attention to athlete health. “At the same time, caution should not lead to complacency,” Perry added. “The pattern we found fits into broader concerns about traumatic brain injury, behavioral regulation, and long-term functioning. For a league built around repetitive physical contact, this should be treated as a player support issue, not just a discipline issue.”
The model used in the study was not adjusted and did not take into account demographic factors such as socioeconomic status, income, or education level. Furthermore, the researchers were unable to account for the players’ field positions. Player position can influence both concussion risk and general behavioral trends, making it an important factor to consider in future work. Reliance on official injury reports also means that undiagnosed concussions are not recorded in the data.
The researchers suggest that the findings have direct relevance to how sports organizations address player safety. “The main lesson is that head injuries have implications for behavioral health and criminal justice interactions, and we should take them seriously,” Perry said. “In our study, NFL players who recorded concussions had higher odds of booking-based arrest in an unadjusted analysis. This should not be interpreted to say that concussions make people criminals.”
Instead, the data show a complex intersection of health and behavior. “This means that brain health, behavior, and contact with the justice system may intersect in populations with high head impacts, and that intersection requires better data, better monitoring, and stronger long-term support for athletes,” Perry said. Improved access to counseling and psychological services during recovery could support athletes who experience changes in emotional regulation and impulse control after injury.
Looking to the future, the researchers hope to further develop this basic research. “My long-term goal is to better understand how head injuries, behavioral regulation, and criminal justice interactions intersect, especially in populations exposed to repeated head impacts,” Perry said. “The next step on this topic is a more robust longitudinal study that would better capture lifetime head injury exposure, positions played, years of football exposure, concussion severity, pre-NFL contact with criminal justice personnel, and post-career outcomes.”
The authors also advocate changing the way sports leagues address these challenges. “I think future efforts should go beyond just asking how the league responds after misconduct occurs,” Perry explained. “A stronger long-term model would focus more directly on prevention, post-injury monitoring, behavioral health support, and transitional care after a player leaves the league. If a head injury can impact sleep, mood, impulse control, or emotional regulation, support systems need to be built around those risks before it becomes a crisis.”
Ultimately, this research calls for a more comprehensive approach to athlete health. “I see this study as part of a broader conversation that player safety needs to include not only what happens on the field and within concussion protocols, but also long-term brain health,” Perry said. “Professional football is an environment where head impacts are high, and players should not have to deal with the possible after-effects of those impacts on their own.”
The researchers hope their work will lead to meaningful change in the sports world. “The league has the resources to think about a player’s health throughout their career: pre-injury, post-injury and post-retirement,” Perry concluded. “My hope is that this research will encourage conversations about support, prevention and long-term care, not just punishment after something goes wrong.”
The study, “Stubborn and Flagged Later: Concussion and Arrest Risk Among NFL Players,” was authored by Jackson Perry, Kimberly Klass, and Burrell Vann Jr.
