Police: Police Officer Behavior

In general, police research has focused on explaining four particular types of police officer behavior: detection activities, service activities, the use of arrest/citations, and the use of force (Sherman, 1980). Detection activities include field interrogation and traffic stops, investigative techniques, etc. Service activities include mediating disputes, assisting citizens, and engaging in problem solving and community policing activities. Official police action is examined through the use of arrest or citations. It is through these actions that police invoke the criminal justice system and bring the power of the state to bear on individuals. Finally, police use of force, although statistically a rare event, has been extensively examined. In the 1960s and early 1970s, much of the research focused on examining the relationship between one predictor variable (e.g., suspects' race) and one outcome variable (e.g., police use of arrest). As research advanced, however, more refined statistical techniques enabled researchers to examine the influence of multiple explanations of police behavior simultaneously.

The factors that explain police behavior have also been generally grouped in four categories: situational, individual, organizational. and community (Sherman; Riksheim and Chermak). Situational factors refer to the characteristics of police-citizen encounters that may influence how an officer acts during that situation. These situational factors include the characteristics of the suspect (e.g., race, sex, age, demeanor, etc.), characteristics of the victim (e.g., race, sex, age, relationship to the suspect, etc.), characteristics of the situation (e.g., location, number of bystanders present, etc.), and legal characteristics (e.g., presence and amount of evidence, seriousness of the offense, etc.). Individual factors refer to the characteristics of individual officers that may influence their behavior (e.g., officers' sex, race, age, attitudes, education, training, etc.). Organizational factors include any characteristics of the police organization that might influence officer behavior (e.g., administrators' preferences, formal and informal policies, departmental size, levels of supervision, etc.). Finally, researchers have also speculated that community factors (e.g., public expectations and preferences, crime rates, demographic characteristics, political characteristics, etc.) may influence officer decisionmaking. The research findings regarding the relative influence of specific factors over police behavior from each of these four groups (situational, individual, organizational, and community) are described below.

Situational/legal characteristics. Situational factors that explain police behavior can be subdivided into four categories: (1) suspect characteristics; (2) victim characteristics; (3) characteristics of the police-citizen encounter; and (4) legal characteristics. As a whole, situational characteristics—particularly legal characteristics—have a relatively strong influence over officer behavior.

Suspect characteristics. Suspect characteristics are perhaps the most controversial potential influences over officer behavior. Do officers make decisions in whole or in part due to the sex, race, age, socioeconomic status, or demeanor of suspects? There has been a particularly strong focus in quantitative research to examine the effects of nonlegal variables on officer behavior. It has been reported that these nonlegal variables typically explain a relatively small portion of the variance in comparison to legally relevant variables, but they have been accorded a great deal of attention. The reason for that attention is that nonlegal variables should not influence the behavior of criminal justice agents if the U.S. system is to be considered legitimate, fair, and just.

Suspects' race/ethnicity. Some minority groups allege that they are singled out by police. They argue that officers often make decisions—field interrogation stops, traffic stops, arrest, and use of force—based on racial considerations. This belief is so widespread among minority communities that the phenomenon has been labeled DWB or "driving while black." A large body of research has accumulated that examines whether or not officers' behavior is influenced by a suspect's race. Collectively, these findings have been somewhat mixed based on the type of officer behavior that is examined.

Studies that have considered officers' decision-making during detection activities (e.g., field interrogation stops, pat down searches, and traffic stops) have generally found that suspects' race does have an influence over officer behavior. For example, the San Diego field interrogation study in the early 1970s reported that 66 percent of citizens stopped for questioning by police were African American and Mexican American males, but they only represent 30 percent of the local population. Likewise, a lawsuit filed in 1993 by the American Civil Liberties Union (ACLU) against the Maryland State Police cited evidence that 73 percent of drivers stopped by officers were African American even though they represent only 17 percent of all drivers (Wilkins v. Maryland State Police; see Walker). In 2000, internal documents from the New Jersey State Police (NJSP) indicated that officers were trained to identify potential drug traffickers based on race.

Disparities and discrimination in field interrogations are a major cause of tension between police and minority communities. While many officers believe aggressive field interrogations and traffic stops are legitimate, effective crime-fighting tactics, they are perceived as harassment by some segments of the population. Aggressive anticrime tactics may result in the racial stereotyping of possible suspects, which is often reinforced by departmental policies. For example, the Christopher Commission in 1991 concluded that the aggressive style of the Los Angeles Police Department (LAPD) constituted an attack on minorities and their communities.

Minority suspects are arrested at disproportional rates to their representation in the population. For example, African Americans represented 31 percent of all arrests, 38 percent of all index crime arrests, and 44 percent of all violent crime arrests, however, they represented just 12 percent of the U.S. population (Walker, Spohn, and DeLone, p. 88). While these figures certainly display disparity in arrest, the larger question is whether this disparity is based on race—that is, whether or not there is discrimination. Some studies utilizing data collected in the late 1970s reported that officers did make arrest decisions based, in part, on the suspect's race (Smith and Visher; Robert Worden, 1989). Nevertheless, in their review of studies examining police behavior, Riksheim and Chermak concluded "utilizing a variety of data sets and examining various offenses, most of these studies found that race had no effect on police arrest decisions" (p. 365). Some have speculated that while suspects' race does not have a direct influence over officers' behavior, it may have an indirect effect operating through other factors such as suspects' demeanor, offense seriousness, and the preference of the victim (Walker et al).

Although police use of force against suspects occurs relatively infrequently, researchers have studied the phenomenon extensively. This attention is most likely due to the severe implications the behavior has for individuals, communities, and the society at large. The use of excessive force—or brutality—by police officers is a source or great strain in police-community relations, particularly in minority communities. Widely publicized examples of police brutality in the 1990s—including the beating of Rodney King in Los Angeles, the physical and sexual assault of Abner Louima in New York City, and the killing of Amadou Diallo, also in New York City—have led to a renewed police-community crisis similar to that experienced in the 1960s. Studies routinely show that minorities are overrepresented as suspects who have force used against them, and who are shot or killed by officers. Robert Worden's (1996) analysis of 1977 data showed that police were more likely to use both reasonable and unreasonable force against black male suspects. Research conducted prior to the U.S. Supreme Court ruling in Tennessee v. Garner, 471 U.S. 1 (1985), which placed constitutional limits on the use of deadly force by police, concluded that officers were more likely to use force, particularly deadly force, against African American suspects (Fyfe). Changes in administrative policies guiding the use of deadly force, however, led to decreases in the use of deadly force. Specifically, adopting the defense-of-life rule significantly reduced the racial disparity in police shootings and reduced firearm discharges in both Memphis and New York City (Fyfe). Other data showed that the ratio of African Americans to whites who had deadly force used against them decreased from seven-to-one to three-to-one from 1970 to 1984. Current studies have reported mixed results regarding the influence of suspects' race over police use of force (for review, see Riksheim and Chermak; Robert Worden, 1996).

Suspects' sex. Several theorists have speculated that female suspects are less likely to be arrested than male suspects because officers are more likely to act in a chivalrous manner by protecting women from criminal sanction (Visher). Research prior to 1980 did indicate that female suspects were less likely to be arrested compared to males (Sherman). A review of the more recent empirical research, however, concluded, "gender was not an important predictor of arrest" (Riksheim and Chermak, p. 365; also see Visher). Of the twenty-six empirical studies reviewed by these researchers, twenty-one reported no relationship between gender and arrest when other factors were controlled. Some research on the use of force, however, has reported that male suspects are at a slightly higher risk to have force used against them compared to female suspects (Robert Worden, 1996).

Other researchers have speculated that the chivalry hypothesis applied only to women who act in a stereotypically feminine manner. Those women who break this stereotype (by engaging in prostitution, or acting in a hostile or aggressive fashion, or simply because they are part of a minority group) are more likely to be arrested. As a result, hostile women, particularly hostile women of color, may be at increased risk of coercive police action relative to hostile male suspects. This hypothesis, however, was not supported when tested empirically (Visher; Engel, Sobol, and Worden).

Suspects' age. Although handling juvenile incidents is believed to be a special problem, researchers know very little about actual street interactions between police and juveniles. Research conducted in the 1960s suggests that officers are more likely to initiate contact with juveniles than with adults and that officers have a large amount of discretion during these encounters. This research also shows that taking no official action is the most likely outcome of encounters with juveniles. When arrest is used, it is more likely in situations that are more serious, when victims request arrest, and the juvenile suspect acts in a hostile manner toward police (Black and Reiss).

Much of the research that has empirically examined arrest and the use of force indicated that suspects' age is not a significant predictor of police decision-making (Riksheim and Chermak). Findings from the most recent systematic observation data set—the Project on Policing Neighborhoods (1996–1997)—also indicated that suspects' age is not a significant predictor of arrest (Engel and Silver).

Suspects' socioeconomic status. Early qualitative studies suggested that suspects' socioeconomic status had an influence over police behavior and bivariate results from studies prior to the 1980s consistently found that lower class suspects were more likely to be arrested (Sherman). Since an individual's socioeconomic status is highly correlated with race in American society, multivariate statistical models are needed to disentangle this relationship. Multivariate studies have found that suspects' level of wealth has no independent influence over officers' decision to arrest (Engel and Silver). Another study has reported that the influence of suspects' class is contingent upon officers' attitudes toward community policing (Mastrofski, Worden, and Snipes). One of the few studies to consider the effect of suspects' class over police use of force found that this variable had no influence after other factors were controlled in a statistical model (Friedrich). Collectively, the evidence regarding the influence of suspects' socioeconomic status is best described as mixed.

Other suspect characteristics: mental status, demeanor, intoxication. Several other suspect characteristics—mental status, demeanor, and intoxication—have widely been considered strong predictors of police behavior. For each of these variables, however, recent studies have challenged conventional wisdom regarding their influence over officer behavior.

As a result of deinstitutionalization, police calls to incidents involving citizens with mental disorders have increased significantly, leading to increases in criminal justice processing of these citizens. It is unclear, however, how a suspect's mental status influences police behavior. Few empirical studies have examined the relative probabilities of arrest for mentally ill versus nonmentally ill suspects. Teplin's study of police discretion toward mentally ill citizens in Chicago found the probability of being arrested was approximately 20 percent higher for mentally ill suspects compared to non-mentally ill suspects. This study, however, reported bivariate relationships and did not adequately control for other factors that could influence police decisions to arrest. After controlling for other situational and legal factors known to influence police decisionmaking, Engel and Silver found that mentally disordered suspects were significantly less likely to be arrested. Police have a large amount of discretion available to them when deciding what course to take regarding mentally ill suspects. Observations of the police suggest that they are more likely to use informal means to handle situations involving mentally ill citizens. For example, officers often use "psychiatric first aid" as an alternative to hospitalization or arrest (Teplin).

A large body of research has indicated that suspects who acted in a hostile or disrespectful manner toward police were significantly more likely to be the recipients of coercive police actions. This body of research, however, was strongly criticized by David Klinger (1994) for not adequately controlling for the seriousness of the offense and for interpreting illegal offenses (for which suspects could be arrested) as displays of a disrespectful demeanor. After taking these criticisms into account, current research continues to show a strong relationship between suspect demeanor and officer behavior (Worden and Shepard). Suspects who act in a disrespectful or hostile manner toward police are significantly more likely to be arrested, issued citations, and have force used against them.

Suspects who are under the influence of alcohol and/or drugs are also significantly more likely to be the recipients of coercive police actions. Research findings have consistently shown that intoxicated suspects are more likely to be stopped and questioned, arrested, issued citations, and have force used against them (Robert Worden, 1989; Riksheim and Chermak). Recent research, however, has suggested that the sobriety of a suspect does not have an independent effect on arrest when the sobriety and demeanor of a suspect are considered together (Engel et al.). This research suggested that intoxication itself does not lead to arrest but that intoxication combined with displays of disrespect place suspects in greater risk for coercive police action.

Victims' characteristics. The bulk of empirical research examining the influence of victims' characteristics on police behavior have focused on the victims' preference (or request) for an arrest, and the relationship between the victim and the suspect. Research findings have consistently reported that victim preference has a strong influence over officers' decisions to arrest. If a victim requests that the offender be arrested, officers are more likely to arrest; conversely, if a victim requests that the offender not be arrested, officers are significantly less likely to arrest (Smith and Visher). Visher reported that female victims requesting arrest have a stronger influence over officer behavior than male victims who request arrest. In a recent study of police behavior, Mastrofski and colleagues reported that officers granted complainants' requests for the most restrictive form of control in 70 percent of the incidents observed.

The relationship between the victim and the suspect has also consistently predicted officer behavior. Studies prior to the 1980s consistently reported a bivariate relationship between the victim-offender relationship and officer behavior; officers were more likely to arrest if the relationship was more distant (Sherman). Multivariate findings have confirmed these early findings. For example, Smith and Visher have found that if the victim and suspect are strangers, officers are significantly more likely to arrest the offender. Alternatively, if the victim and suspect are well-acquainted, officers are significantly less likely to arrest.

Only a few studies have considered the influence of individual characteristics of the victim. The majority of findings indicated that the complainants' race had no influence over officers' detection activities and decisions to arrest. For example, one study found that the race of domestic violence victims had no influence over police behavior in those disturbances (for review see Sherman; Riksheim and Chermak). Mastrofski and his colleagues reported that officers were significantly less likely to grant citizens' requests to control another citizen when the complainant was disrespectful to the police, intoxicated, mentally disordered, or involved in a close relationship with the other citizen.

Characteristics of the police-citizen encounter. Research regarding the influence of the characteristics of situations have produced mixed results. Research reviewed by Sherman showed that police were more likely to arrest suspects in situations where the police entered the encounter proactively (i.e., not in response to a citizen or dispatched request for service). More recent research, however, has shown that police entry does not have a significant influence over arrest behavior (Mastrofski et al., 1995; Engel and Silver). Likewise, the location of a police-citizen encounter as either public or private does not have an influence over police decisions to arrest or use force (Worden and Shepard; Engel et al.). Other factors, such as the presence of bystanders and the presence of additional officers, have been shown to increase police use of force, but not the use of arrest (Engel et al.). However, as noted by Riksheim and Chermak, "the influence of most situational characteristics on arrest behavior remains unresolved" (p. 365).

Legal characteristics. Legal considerations appear to have the strongest and most consistent influence over police behaviors (i.e., detection activities, arrest/citations, and use of force). Legal factors include the seriousness of the offense, amount and type of evidence, injury of the victim, presence of a weapon, suspect's prior record, and if the suspect is currently wanted for a prior offense. While researchers' initial measures of legal variables were rather crude, more precise measures continue to show a strong relationship to police behavior. For example, offense seriousness was routinely measured as a dichotomous variable representing a felony or misdemeanor offense; however, this variable is measured as an ordinal scale to capture greater variation in levels of seriousness (Klinger, 1994).

Most studies of police arrest behavior have confirmed that legal factors have the strongest influence over police arrest decisions. Mastrofski and his colleagues (2000) reported that legal considerations (e.g., evidence of suspects' and complainants' wrongdoing, citizens' requests for arrest) were the most influential factors explaining officers' decisions to respond to citizens' requests to control another citizen. Earlier work by Mastrofski and others (1995) showed that legal factors accounted for 70 percent of the explained variance in officers' decisions to arrest—the majority of this explanatory power was from the strength of the evidence. Likewise, other studies have found that legal considerations strongly and consistently predict officers' use of force (Robert Worden, 1996). Klinger also found that legal considerations had a stronger influence over police behavior than suspects' demeanor, and concluded that researchers must make greater efforts to consider the influence of legal factors in their studies of arrest and other officer discretionary action.

To summarize, there is some evidence that particular types of citizens—racial and ethnic minorities, particularly African American males—are subject to differential treatment by police officers. Legal factors, however, play a much greater role in explaining officer behavior. Nevertheless, widely publicized incidents have accumulated over time and created a perception of systematic police harassment of minority citizens. As noted by Walker, this evidence, combined with citizens' perceptions of discrimination and disparity, created a police-citizen relations crisis in the 1980s and 1990s.