An Overview of Police Use of Force Policies and Research

Introduction

The relationship between the police and public has become increasingly tenuous following a series of highly publicized police killings.^[1] These include the deaths of George Floyd, Breonna Taylor, Eric Garner, and Elijah McClain. In addition, data reveals notable racial disparities in police use of force. Although approximately 1,000 civilians in the U.S. are killed by police officers each year, Black men are 2.5 times more likely than their White counterparts to die at the hands of an officer.^[2] Studies also have shown that persons of color, persons with mental illness, and persons who identify as lesbian, gay, bisexual, transgender, or queer/questioning (LGBTQ+) have increased likelihood of experiencing force.^[3] The disparities in police use of force have long been a source of controversy, sparking numerous protests and calls for reform throughout the country.^[4]

Although there is national data on police use of force, it is limited, which creates barriers to research and reform efforts. Without comprehensive and accurate data to illustrate the true extent and causes of police force overuse, mistrust between law enforcement and communities builds, and each side is left to develop their own narratives on the issue.^[5] Public demands for transparency and policy reform underscore the need for continued conversation between communities and police to protect both citizens and officers.

This literature review defines police use of force and provides an overview of policies and research on use of force. In addition, we describe theories offering potential explanations on why force overuse occurs, as well as seminal court cases involving use of force decision-making.

Defining Use of Force

Police are empowered to use force against an individual or individuals to defend themselves and others.^[6] Police use of force is not universally defined. The most commonly accepted definition was developed by the International Association of Chiefs of Police (IACP), which defines police use of force as the “amount of effort required by police to compel compliance by an unwilling subject.”^[7] Although use of force is often conceptualized as physical force, at its most basic, use of force may refer to verbal commands issued by officers to direct individuals through certain actions (e.g., “Don’t move.” “Hands up.”).^[8]

Defining Excessive Force

Illinois statutory language describes that “[an officer] is justified in the use of any force which he reasonably believes, based on the totality of the circumstances, to be necessary to effect the arrest and of any force which he reasonably believes, based on the totality of the circumstances, to be necessary to defend himself or another from bodily harm while making the arrest.”^[9] Therefore, use of excessive force may refer to instances where an officer uses more force than what is reasonably believed to be necessary in that circumstance.^[10] Notedly, this is sometimes differentiated from “excessive use of force” (i.e., unnecessary use of force), which implies police officers using force too often in their contacts with citizens.^[11]

Use of excessive force can encompass situations that go beyond one-on-one encounters. This type of force may be witnessed at peaceful protests where police use unnecessary riot control tactics.^[12] Public health scholars argue that excessive force can extend to psychological intimidation, sexual and emotional violence, and verbal assault.^[13]

The definition of “excessive” in the context of force has been heavily debated and impacted by many legal cases. In 1989, in Graham v. Connor, the U.S. Supreme Court ruled on police use of excessive force. In the case, Dethorne Graham, a person with diabetes, had an insulin reaction prior to being pulled over. He resisted arrest, but police officers ignored his attempts to explain his medical condition, and he was ultimately injured. Though Graham asserted the force was excessive, the Court decided that the appropriate level of force in a situation must be judged by the “objective reasonableness” standard. The standard states that whether force used was excessive or not must be viewed from the perspective of how another “objectively reasonable” officer would have reacted in that moment, without benefit of hindsight. This ruling recognized the inherent dangers of police work, which often requires split-second decision-making, though critics argue the ruling fails to acknowledge the rights of citizens affected by law enforcement action.^[14]

Use of excessive force is also referred to broadly as police brutality, though the terms excessive force and police brutality may be defined differently across demographic groups (e.g., police officers, citizens, people of different genders, people of different races).^[15] Personal definitions may also differ from the legal definition of excessive force which can create additional misunderstanding between police, communities, scholars, and government systems.^[16] Some researchers have asserted the importance of revising excessive force definitions and including communities in this process. Previous standards have been primarily determined by the courts and filtered through police departments that may be inclined to interpret the law to suit their interests.^[17] As Obasogie and Newman (2019) described in the Cornell Law Review, having a policy that officers must simply act “reasonably” in situations involving force creates ambiguity and “transforms use-of-force policies into devices that can insulate the police from liability instead of protecting citizens from constitutionally-violative excessive force” (p. 1322).^[18]

Use of Force Rulings and Policies

Prior to 1985, certain U.S. state courts ruled that any use of force, including deadly use, was reasonable in the case of a fleeing felon.^[19] However, in 1985, in Tennessee v. Garner, the U.S. Supreme Court ruled that laws authorizing police use of deadly force to apprehend fleeing, felony suspects are unconstitutional unless there is probable cause to believe that the suspect poses a significant threat of death or serious physical injury to the officer or others.^[20] Ultimately, many police departments adopted the view that deadly force must only be used in self-defense or defense of others, nationally reducing police homicides.^[21] Though Garner impacted use of force policies regarding fleeing felons, the objective reasonableness standard still applies in incidents related to force. Legal scholars continue to debate on the interpretation and impact of the Garner case.^[22]

The Police Use of Force Project, created through the efforts of civil rights activists and researchers, found police use of force policies vary in their requirements. In a review of 91 of 100 police departments in the largest U.S. cities, they found that only 34 of the 91 departments required officers to de-escalate situations prior to using force. Only 21 departments explicitly prohibited chokeholds and strangleholds, and only 56 required officers to provide a warning before deadly force was used.^[23] The project concluded that police department policies can have a great effect on how and when force is used by officers and that more restrictive policies can both protect officers and reduce police killings. The following are examples of the use of force policies of Illinois’ largest cities:

• Chicago
• Aurora
• Naperville
• Rockford
• Springfield

Use of Force Continuum

Due to the fluidity of situations where officers may need to use force, police use of force is often conceptualized on a spectrum.^[24] Officers typically follow guidelines that dictate the level of force that should be used in certain situations. However, Foster (2020) noted there is no single applicable law that governs use of force by law enforcement.^[25] Police departments may reference one of several use of force continuums to guide appropriate responses (Figure 1). Some departments follow linear models, while others use wheels or matrices.^[26] At the department level, Terrill et al. (2011) discovered a wide variation in force continuum policy; some departments considered chemical sprays and energy devices (e.g., TASERs) to be at the same level of force, while others listed them at distinct levels.^[27] Therefore, having a continuum does not necessarily signify standardized measurements of force across departments.

Figure 1

Example Linear Use of Force Continuum

Note. Adapted from National Institute of Justice. (2009). The use-of-force continuum. https://nij.ojp.gov/topics/articles/use-force-continuum

Continuums do generally share similar terminology. A “compliant citizen” follows all directions issued by an officer. Therefore, the officer does not need to use physical force and can use verbal commands to generate compliance. For citizens who do not fight back but ignore an officer’s orders (or are “passively resistant”), officers may apply contact controls that can be painful without resulting in serious injury. Citizens who are “actively resistant,” or fighting back, may encounter stronger compliance techniques resulting in harm to the individual. Citizens who impose a “serious threat,” one that could kill an officer or another civilian, may encounter lethal force. Research and policy debates often focus on this highest level of force.^[28]

Although a popular method, linear force continuums have raised criticism. Wallentine (2009) suggested police officers are often placed in ever-evolving situations that cannot be neatly transposed to a static continuum.^[29] They argued that legal, practical, and scenario training are more appropriate to teach officers to use force through threat assessment skills development and action and response sequences.^[30] In addition, the Police Executive Research Forum (PERF) argued that linear continuums place the focus on how officers should use force in a situation, as opposed to de-escalation or communication strategies.^[31] Instead, PERF suggested alternative approaches, such as the critical decision-making model. This model focuses on assessing risks and allows officers more flexibility on how to proceed. Preliminary research suggests officers may misunderstand or resist this model. Researchers have recommended future studies examine how new force-related policies can be effectively implemented.^[32]

Theories Related to Why Police Use Force

Within the literature, numerous overarching theories have been suggested to explain police use of force, including:^[33]

• Individual officers’ dispositions.
• Situational factors, such as alleged offense or suspect attitude and resistance.
• Organizational policies and culture.^[34]

Individual officer theories include the “rotten apples” hypothesis.^[35] This theory suggests police misconduct and excessive force can be attributed to a few bad officers, as opposed to a broader policing issue. Research on this hypothesis has provided some evidence to support the theory; a review of the Los Angeles Police Department found that of its 8,450 sworn personnel, 183 officers had received four or more allegations of excessive force, 44 had received six or more complaints, and 16 had eight or more.^[36] However, researchers have noted this theory may absolve departments and administrators from responsibility and allow departments to avoid acknowledging how police culture shapes use of force in their departments and the process of how “good” officers can become “rotten” officers.^[37]

Situational theories suggest that context plays a role in when force is used; for example, it could be theorized that officers who patrol high-crime or dangerous areas may use more force. Hine et al. (2016) examined situational variables that could impact whether an officer uses force, including police district and setting, season and time of day, number of officers and suspects, suspect behavior, and suspect gender and age. In their study of 154 police-citizen encounters that involved force, they found support for situational theories of force—specifically, the association between individual suspect behavior and officer’s use of force.^[38]

Finally, organizational and police culture may also impact officer’s views on civilians and their use of force. Research posits that officers assimilate to traditional police culture in order to cope with the work-related stressors of being an officer.^[39] This culture encompasses distrust toward citizens, loyalty to fellow officers, and allowance of misconduct, but officers can vary individually in their endorsement of these beliefs. Silver et al. (2017) found that strong endorsement of traditional police culture was associated with more support for use of force, which produced stronger effects than the other individual, organizational, and contextual factors in their model.^[40]

“Recognizing that many who serve in law enforcement are committed to justice, the violence inflicted by police in news headlines today must be understood in relation to larger social and economic arrangements that put individuals and populations in harm’s way, leading to premature illness and death.”

Ehrenfeld, J. M., & Harris, P. A. (2020). Police brutality must stop. American Medical Association. https://www.ama-assn.org/about/leadership/police-brutality-must-stop

Smith and Holmes (2014) offered three additional hypotheses for excessive uses of force that focus on the contributions of structural inequality and racism in departments:^[41]

• Minority threat hypothesis suggests coercive controls by police aid in social control for the dominant societal group. Therefore, the greater the numbers of a minority population in an area, the greater the threat of a proportionally greater police response.
• Place hypothesis poses that police use force in certain communities, mainly highly concentrated, underserved communities of color in urban areas, leading to distrust or resistance to police and escalating conflict.^[42]
• Community accountability hypothesis suggests departmental characteristics play a role in use of force. Police departments, which are hierarchical and militaristic in nature, can create a subculture that glorifies violence and upholds police loyalty, even in the face of misconduct.^[43]

Ultimately, Smith and Holmes found support for the minority threat hypothesis and suggested police as a whole serve to enforce structural social divisions.^[44]

No one theory can address all factors that contribute to use of force incidents.^[45] What can be most clearly identified, however, is that though use of deadly force is typically restricted within individual department policies, it is still a decision made at the law enforcement officer’s discretion.^[46]

Use of Force Data

Use of force data was not publicly accessible until the 1960s-1980s.^[47] Before that, law enforcement agencies either failed to keep records of instances of use of force or denied access to those records.^[48] Police use of force data is sometimes obtained by local media through court orders and Freedom of Information Act requests.^[49] The data is often aggregated, hiding association to individuals, cases, or specific departments, districts, or officers.^[50]

Little data is available nationally on law enforcement officer use of force.^[51] The Federal Bureau of Investigation (FBI) implemented the National Use of Force Data Collection system in 2019. However, participation is voluntary, and only 8,226 of 18,514 (44%) of law enforcement agencies participated in 2021, representing 63% of the country’s sworn officers.^[52] Due to federal regulations, the FBI can only release a certain amount of information until 80% of sworn officers are represented in the data. As only half of the benchmark has been met, for now, only information on participating law enforcement agencies is available and without individual incident details. In Illinois, 291 of 989 agencies (29%) participated in 2021 in FBI data collection, representing 36% of sworn officers in the state.

News outlets have shared concerns that the FBI may never reach the required threshold to release its force data, but there have been efforts to push for increased participation.^[53] A report from the U.S. Government Accountability Office recommended a review of where and how delays in the data collection and reporting are occurring, and if needed, an investigation of alternative collection strategies.^[54] Some cities publish more detailed information. For example, the Chicago Police Department releases more specific data on its Use of Force Dashboard, which can be filtered by gender, race, age, and more.

To address the lack of use of force data, citizens and organizations throughout the country have taken steps to compile national statistics for use by researchers and the public. Examples include Fatal Encounters, The Washington Post, and Mapping Police Violence databases.

Research on Use of Force

Researchers are challenged to study police use of force without a universal definition. The use of varying methodologies have arrived at mixed, and sometimes conflicting, results.^[55] Differences in how the severity of force used is measured can make it difficult to compile findings from available research.

Some research indicates police use of force is relatively rare, but a number of factors may affect reporting. Alpert and MacDonald (2001) examined data from a national sample of 265 law enforcement agencies to determine the impact of agency-related characteristics on aggregate rates of reported police use of force. They found that agencies that required supervisors to fill out use of force forms reported significantly lowered rates of force than agencies that had officers fill out their personal forms.^[56] Other research revealed officers with certain location assignments (e.g., high crime areas)^[57] and officer peer groups (i.e., those with propensity for aggression)^[58] can affect use of force rates. A 2008 study found force is used or threatened in less than 20% of arrest cases; this percentage dwindled to less than 5% of police contacts outside of arrest situations.^[59] Morrow et al. (2017) examined stop, question, and frisk data from the New York Police Department in 2012 and found that force was used in 14% of stops, with weapon force even rarer in only .01% of stops.^[60] Improvements to the FBI National Use of Force Data Collection may assist researchers with continuing to examine more recent use of force statistics.

Race and Use of Force

Despite officers infrequently using force overall, certain groups encounter a disproportionate amount of police violence. Studies have repeatedly shown that people of color are most affected by police use of force.^[61] In particular, Kahn et al. (2017) found that Black and Latinx individuals encounter more use of force in the beginning stages of police interaction than their White counterparts.^[62]

Motley and Joe (2018) noted that income and gender can also intersect with race to affect use of force during police contact. They found that Black men and White women with incomes of less than $50,000, as well as Black women with incomes of more than $50,000, had a significantly increased risk for police use of force than Black and White persons from other income groups.^[63] The authors suggested that this finding could be interpreted within the context of the minority threat theory, in that the police are used to maintain control over less dominant societal groups.

Edwards and colleagues (2019) found that police use of force was the sixth most common cause of death among young American men (ages 25-29), at a mortality rate of 1.8 deaths per 100,000.^[64] This rate followed accidents (e.g., drug overdoses, motor vehicle deaths; 76.6 per 100,000), suicide (26.7 per 100,000), homicides (22.0 per 100,000), heart disease (7.0 per 100,000), and cancer (6.3 per 100,000). The authors noted that police use of force was not among the top 15 causes of death for young women. Although their research indicated the threat of death by police peaked significantly between the ages of 20 and 35 for men and women in all racial and ethnic groups, they also found that Black and Latinx men were more likely than White men to be killed by police (Figure 2). Their estimates suggested that young Black men, ages 25-29, were killed by police at a rate ranging from 2.8 to 4.1 per 100,000, over double that of White men, ranging from 0.9 to 1.4 per 100,000.^[65]

Figure 2

Estimated Lifetime Risk of Being Killed by the Police

Note. Adapted from Edwards, F., Lee, H., & Esposito, M. (2019). Risk of being killed by police use of force in the United States by age, race-ethnicity, and sex. Proceedings of the National Academy of Sciences of the United States of America, 116(34), 16973-16798. https://doi.org/10.1073/pnas.1821204116

While police violence is not reflected in the Centers for Disease Control and Prevention’s (CDC) leading causes of death among young men, research in The Lancet found that more than half of all deaths due to police violence went unreported in the National Vital Statistics System used by the CDC when comparing it to other open-source databases on police violence.^[66] The researchers suggested that better training is needed to capture this datapoint in death certificates and medical reports.

Finally, Lett et al. (2020) examined years of life lost due to fatal police shootings. This was calculated by comparing life expectancy and age at death among U.S. citizens by race. They found that Black and Native American populations had three to four times the number of years of life lost than White populations, and Asian populations had half the number of years of life lost compared to White populations.^[67] The authors noted that this “suggests that racism alone does not explain [the] results,” and that the findings “suggest the influence of an insidious anti-Black and anti-Indigenous logic to police violence that warrants further exploration into the role of these factors in fatal police encounters” (p. 3).

Persons with Mental Illness and Use of Force

Research has found disparities in the amount of police force applied to persons with mental illness. A 2015 report from the Treatment Advocacy Center found that persons with untreated mental illness were 16 times more likely to be killed during police contact than other civilians, reflecting the overrepresentation of this population throughout the criminal justice system.^[68] Similarly, Saleh et al. (2018) found that almost one-fourth of police fatalities involved persons with mental illness.^[69]

Some research found persons with mental illness may also be more likely to resist arrest, which may relate to how and when police use force. Mulvey and White (2014) suggested that officers may be more tolerant and sympathetic to low-level resistance from persons with mental illness, but higher-level resistance may be met with increased amounts of force.^[70] Rossler and Terrill (2017) found persons with mental illness were injured in one out of three encounters with police, while persons without mental illness were injured in one out of four encounters.^[71] They suggested that future research should more closely examine how officers determine if citizen behavior is related to mental illness and why officers may use more force in those encounters in order to adjust departmental policies and training.

In 2018, the U.S. Commission on Civil Rights encouraged training on mental illness and de-escalation (such as crisis intervention training) for police to address those disparities and build trust with communities.^[72] Crisis intervention training teaches officers to recognize the symptoms of mental illness and develop verbal de-escalation skills to avoid the need for force. Fostering relationships between community mental health providers and law enforcement, as well as allocating resources to mental health training, may be integral steps for effective use of these strategies.^[73]

LGBTQ+ Populations and Use of Force

Police use of force regarding members of the LGBTQ+ community is a growing concern. Those who identify as LGBTQ+ have cited negative experiences with the police, including harassment, assault, and excessive force.^[74] DeVylder et al. (2018) conducted a survey of adults residing in Baltimore and New York City and found LGBTQ+ individuals were disproportionately affected by police violence exposure when compared to non-LGBTQ+ individuals.^[75] In Gaynor and Blessett (2022), LGBTQ+ people of color described experiences with police involving verbal harassment, intimidation, and perceived abuse of power.^[76] In narrative interviews and statements, their participants noted a sense of lacking rights in interactions with police, with Black transgender women specifically highlighting targeted discrimination.

Overall, calculating rates and identifying trends for these populations is challenging due to a lack of widespread, comprehensive data collection. Researchers and advocates have suggested a need for increased academic and policy focus, research, and funding on the effects of police violence on the communities historically harmed by law enforcement.^[77]

Police Reform and Use of Force

States across the country have made several efforts to tackle issues regarding use of force.^[78] The Illinois Safety, Accountability, Fairness and Equity–Today (SAFE-T) Act addresses police use of force among other criminal justice reforms. In the Act, police reforms include:

• Mandated body-worn cameras for all police officers.
• Limits on military equipment.
• Crisis intervention and de-escalation training.
• Restrictions on use of force, including the prohibition of chokeholds and other types of neck restraints unless deadly force is authorized.^[79]

Some law enforcement groups oppose aspects of the SAFE-T Act and feel the Act is vague, overly restrictive, and harmful to law-abiding citizens.^[80] Future studies should assess the impact of this Act on use of force.

To read more about the SAFE-T Act, please see this ICJIA article which offers a detailed overview.

Conclusion

As civil servants, the police have been tasked with the challenging and stressful job of protecting their communities. As such, officers may find themselves in dangerous situations, with only moments to decide between life and death. Although members of the public understand this reality, the deaths of Black Americans, including George Floyd, Breonna Taylor, Michael Brown, Eric Garner, Elijah McClain, Laquan McDonald, and many others, have not been forgotten. These incidents have attracted national attention, increased scrutiny on use of force policies, and impacted relationships between law enforcement and citizens.^[81] Communities that call for police reform seek to reduce, alter, or minimize use of force policies; however, policies can vary greatly by department and jurisdiction.^[82] Departments may struggle on how to enact changes as use of force is deeply reliant upon officer discretion.^[83]

Still, across police departments and locales, research indicates that people of color are more likely to be subjected to use-of-force experiences than White persons, even after controlling for the rate of crime committed by each group.^[84] Persons living in the intersection of marginalized groups, such as Black persons who have a mental illness, have low incomes, or are LGBTQ+, may encounter the highest rates of force. However, researchers encounter inconsistent methodologies and lackluster data when comparing statistics on use of force, pointing to a need for improved data collection. Noted disparities and public outcry must also be adequately addressed by law enforcement departments, the courts, and legislators to begin repairing the relationship between the police and the public and continue a discourse on use of force policy.