U.S. Department of Justice Office of Justice Programs Bureau of Justice Statistics Contacts between Police and the Public, 2008 Special Report Christine Eith and Matthew R. Durose, BJS Statisticians ---------------------------------------------------------- This file is text only without graphics and many of the tables. A Zip archive of the tables in this report in spreadsheet format (.csv) and the full report including tables and graphics in .pdf format are available on BJS website at: http://www.bjs.gov/index.cfm?ty=pbdetail&iid=2229. This report is one in a series. More recent editions may be available. To view a list of all in the series go to http://www.bjs.gov/index.cfm?ty=pbse&sid=18. ----------------------------------------------------------- In 2008, an estimated 16.9% of U.S. residents age 16 or older had face-to-face contact with police. This was a decline from the 19.1% of U.S. residents who reported having contact with police in 2005 and a decrease from the 21% who experienced contact with police in 1999 and 2002 (figure 1). Between 2002 and 2008, about 5.3 million fewer residents had face-to-face contact with police, down to an estimated 40.0 million from 45.3 million. Among persons who had a face-to-face contact with police in 2008, about 1 out of 4 had more than one contact during the year. The public most commonly came into contact with police when driving a vehicle that was pulled over in a traffic stop. Other frequent reasons for contact with police included reporting a crime to police or being involved in a traffic accident. The findings described in this report are based on the Police-Public Contact Survey (PPCS) that the Bureau of Justice Statistics (BJS) periodically uses to interview all persons age 16 or older in a nationally representative sample of households about their contacts with police during the previous 12 months. The PPCS is a supplement to the National Crime Victimization Survey. This report summarizes data from the 2008 PPCS and compares findings to the 2002 and 2005 surveys. ----------------------------------------------------------- Highlights * The percent of U.S. residents age 16 or older who had face to-face contact with police declined from 2002 (21.0%) to 2005 (19.1%) and declined again in 2008 (16.9%). * An estimated 9 out of 10 residents who had contact with police in 2008 felt the police acted properly. * The most common reason for contact with police in 2008 was being a driver in a traffic stop (44.1%). * White (8.4%), black (8.8%), and Hispanic (9.1%) drivers were stopped by police at similar rates in 2008. * Male drivers (9.9%) were stopped at higher rates than female drivers (7.0%). * In 2008 about 5% of traffic stops led to a search. Police were more likely to search male drivers than female drivers. * Black drivers were about three times as likely as white drivers and about two times as likely as Hispanic drivers to be searched during a traffic stop. * During traffic stops in 2008, about 57.7% of searches of the driver only and 60.0% of searches of the vehicle only were conducted with the driver's consent. * About 36.1% of drivers who were only physically searched and 20.7% of drivers who only had their vehicle searched believed police had a legitimate reason to do so. * Among persons who had contact with police in 2008, an estimated 1.4% had force used or threatened against them during their most recent contact, which was not statistically different from the percentages in 2002 (1.5%) and 2005 (1.6%). * A majority of the people who had force used or threatened against them said they felt it was excessive. ----------------------------------------------------------- Police-Public Contact Survey interviewed U.S. households about their face-to-face interactions with law enforcement officers BJS conducted a pilot test of the PPCS in 1996 as a supplement to the National Crime Victimization Survey (NCVS). The 1996 survey was administered to determine whether the NCVS could serve as a useful method for collecting data on contacts between U.S. residents and the police and to obtain preliminary estimates on this topic. The pilot survey revealed that about 21% of the public experienced face-to-face contact with a police officer at least once during 1996. Survey findings helped to inform the development of an improved questionnaire. In addition to the pilot study, a panel of law enforcement experts reviewed and provided recommendations on the survey procedures and questionnaire. A revised version of the PPCS was fielded in 1999 among a national sample nearly 15 times as large as the 1996 pilot sample. The 1999 survey included a more detailed set of questions about traffic stops by police, which was the most frequent reason for contact with police. The 1999 survey yielded estimates similar to those in the 1996 survey on the prevalence and nature of contacts between the public and the police. Since 1999, the PPCS has been administered every 3 years (in 2002, 2005, and 2008) as a supplement to the NCVS. During the survey, U.S. residents age 16 or older were asked whether they had a face-to-face interaction with a law enforcement officer during the 12 months prior to their interview. Survey respondents who said they had face-toface contact with police were asked to describe the nature and outcome of that contact. Persons who reported more than one instance of face-to-face contact during the year were asked to describe the most recent occurrence. Contact with police excluded contact by telephone or written correspondence, contact with private security guards, social contact, or contact that occurred because of employment or volunteer work that brought the respondent into regular contact with police. In addition, members of the household who were living in an institution at the time of the interview--for instance, incarcerated persons--were excluded from the PPCS sample. Such exclusions may affect the findings because contact with police leading to incarceration would involve more serious outcomes. This report summarizes the results of the 2008 PPCS and provides comparative analysis with findings from the surveys conducted in 2002 and 2005. (See Methodology for information on the reasons for limiting certain comparisons to these 3 years.) The findings are based solely on the personal accounts of the PPCS respondents. Official police records on contacts between police and the public were not used in the study. Data collected and described in the report cannot provide a sufficient basis to infer a causal relationship between characteristics of the respondent and police behavior. In comparisons described in the text, an explicit or implied difference indicates that BJS conducted tests of statistical significance, and the difference was significant at the 95% confidence level or above. Certain differences were not significant at or above the 95% level, but were significant at the 90% confidence level. The terms "somewhat," "some indication," "some evidence," or "slightly" refer to differences significant at the 90% level. (See Methodology for more information on confidence intervals and statistical significance tests.) Number of persons who had contact with police declined between 2002 and 2008 In 1999, an estimated 20.9% of U.S. residents age 16 or older experienced face-to-face contact at least once with a police officer. About the same percentage of contact between police and residents (21.0%) occurred in 2002. About 19.1% of residents had face-to-face contact with police in 2005, a decrease from the percentage who had police contact in 2002. In 2008, the percentage of residents who experienced contact with police further decreased to 16.9%. Overall, about 5.3 million fewer residents had face-to-face contact with police during 2008, compared to the total number who had contact in 2002 (table 1). An estimated 45.3 million residents age 16 or older had police contact in 2002, while about 40.0 million had contact with the police in 2008. While the second most common reason for contact with police during this period continued to be reporting a crime or problem, the percentage of all contacts that occurred for this reason decreased from 26.4% in 2002 to 23.7% in 2005 and 20.9% in 2008 (table 2). Nearly 12 million residents said their most recent contact in 2002 was to report a crime or problem to police, compared to about 8.3 million (or 30.2% fewer) residents in 2008. The decline in these contacts accounted for about 3.6 million (69%) of the 5.3 million fewer contacts residents had in 2008 compared to 2002. The drop in the number of residents reporting crimes or other problems to police was consistent with findings from the NCVS that showed a decline in criminal victimization during this period. Between 1999 and 2008, the violent crime rate declined by 41%, and the property crime rate fell by 32%. *** Footnote 1 Criminal Victimization, 2008, NCJ 227777, September 2009 (http://www.bjs.gov).*** In 2002, 2005, and 2008, more than half of residents reported that their most recent contact with police was the result of a traffic stop or accident. The most common reason for police contact all 3 years was a person driving a vehicle that police stopped. Overall, the portion of all contacts that occurred as the result of being a driver in a traffic stop increased from 37.1% in 2002 to 41.0 in 2005 and 44.1% in 2008. Among residents age 16 or older in 2002, the rate of contact that occurred to report a crime or other problem was 5.5% (table 3). This rate decreased to 3.5% in 2008. The rate of contact with police for being a person driving a vehicle that police stopped was 7.8% in 2002 and 7.5% in 2008. The difference between these percentages was not statistically significant. Overall, there was no discernable statistical difference between the number of persons whose most recent contact was as a driver in a traffic stop in 2002 (16.8 million) and 2008 (17.7 million) (table 4). While the difference between the number of male drivers stopped by police in 2002 and 2008 was not statistically significant, the number of female drivers stopped by police increased nearly 12% during this period. The number of white and black drivers stopped by police during their most recent contact did not increase between 2002 and 2008. Among Hispanic drivers, the number of residents stopped by police increased nearly 28%. A decline in the number of persons whose most recent contact with police was to report a crime or other problem between 2002 and 2008 was found among both males and females. White, black, and Hispanic residents also experienced a drop in the number of face-to-face contacts that occurred from reporting a crime or problem during this period. Males had contact with police at higher rates than females The percentage of males experiencing face-to-face contact with police was higher than the percentage of females in 2008 (table 5). Among residents age 16 or older, persons ages 18 to 24 experienced the highest percentage of police contact in 2008. White residents experienced a higher rate of contact with police than black and Hispanic residents in 2008. These differences were consistent with findings from the 2002 and 2005 surveys. In 2005 the racial categories changed from previous years of the PPCS to separately identify persons of other races (American Indians, Alaskan Natives, Asians, Native Hawaiians, and Pacific Islanders) and those of any race indicating two or more races. In 2005 and 2008, the PPCS found that whites were more likely than Asians, Native Hawaiians, and other Pacific Islanders to have contact with police. Whites did not have a higher rate of police contact than American Indians and Alaskan Natives in 2005 or in 2008. Similar patterns were found in the demographic composition of persons who had contact with police in 2002, 2005, and 2008. Males accounted for just over half of all persons who had contact with police during these three years (table 6). White residents made up about threequarters of contacts, and black residents made up about 1 out of 10 persons who had police contact. Hispanic residents also accounted for about 1 out of 10 persons who had contact with police in 2002, 2005, and 2008. About a quarter of persons with contact in 2008 had more than one contact during the year Among persons who had face-to-face contact with police during 2008, about 1 out of 4 (25.1%) experienced contact more than once during the year (table 7). Among the 40.0 million persons who had contact with the police in 2008, nearly 67.0 million encounters occured with an average of 1.7 contacts per resident who experienced police contact. A greater percentage of males (26.9%) than females (23.0%) who had police contact in 2008 experienced more than one contact during the year. Among persons who had contact with police in 2008, black residents (28.4%) were somewhat more likely than white residents (24.6%) and more likely than Asian, Native Hawaiians, and other Pacific Islanders (20.4%) to have multiple contacts. Persons ages 18 to 24 were more likely than older age groups to experience multiple contacts during 2008. A majority of survey respondents said they felt the police acted properly during face-to-face contact As was the case in 2002 (90.1%) and 2005 (90.4%), the vast majority of residents (89.7%) with police contact during 2008 felt the officer or officers acted properly. *** Footnote 2 Findings come from the 2002 and 2005 Contacts between Police and the Public reports. See Methodology.*** In addition, about 9 out of 10 (91.8%) residents who experienced a contact in 2008 reported that the police were respectful (table 8). Overall, most white, black, and Hispanic residents who had contact with police felt the officer or officers acted properly. Opinions about police behavior varied across reasons for contact. For instance, persons who police suspected of wrongdoing or who had contact through a criminal investigation (78.5%) were less likely than those who had contact with police during a traffic accident (92.6%) to feel police behaved properly. Blacks (69.6%) and Hispanics (62.3%) were less likely than whites (82.3%) to believe police acted properly during contacts that occurred because police were investigating a crime or suspected the person of wrong doing. For those who had contact with police in the context of a traffic accident, no differences were found in the estimated percentage of whites, blacks, and Hispanics who felt the police acted properly. Drivers in 2008 were stopped by police at rates similar to those in 2002 and 2005 In 2008, an estimated 17.7 million persons age 16 or older indicated that their most recent contact occurred as a driver pulled over in a traffic stop (table 9). These contacts include stops of all kinds of motor vehicles--for example, motorcycles, buses, and private and commercial cars and trucks--being used for both personal and business travel. Of the estimated 209.2 million who drove during 2008, the 17.7 million drivers stopped by police represented 8.4%--nearly 1 out of 12 drivers. An additional 1.7 million individuals were stopped by police at some point during the 12-month period, but had experienced more recent contact in a different context. In total, an estimated 9.2% of all drivers, about 19.3 million, were stopped at least once by police in 2008. Overall, drivers in 2008 (8.4%) were stopped by police at a rate similar to that of 2002 (8.8%) and 2005 (8.8%). A greater percentage of male drivers (9.9%) than female drivers (7.0%) were stopped by police during 2008. Drivers between the ages of 16 and 29 had a greater likelihood than other age groups of being pulled over by police. These differences were consistent with findings from the 2002 and 2005 surveys. White (8.4%), black (8.8%), and Hispanic (9.1%) drivers were stopped by police at similar rates in 2008. White, black, and Hispanic drivers were also stopped at similar rates in 2002 and 2005. In 2008 white drivers (8.4%) were more likely than Asian, Native Hawaiian, and other Pacific Islander drivers to be stopped (6.3%), but somewhat less likely than American Indian or Alaskan Native drivers (12.6%) to be stopped by police. The likelihood of being stopped by police in 2005 did not differ significantly among white drivers (8.9%), American Indian or Alaskan Native drivers (11.9%), and Asian, Native Hawaiian, and other Pacific Islander drivers (7.9%). Speeding was the reason for about half of all traffic stops The PPCS includes a detailed set of questions for respondents whose most recent contact with police occurred as a driver in a traffic stop. When drivers were asked what reason the officer gave for the traffic stop, the most frequent reason was exceeding the speed limit, cited by about half of drivers stopped in 2002 (54.8%), 2005 (53.7%), and 2008 (50.2%) (table 10). About 1 in 10 drivers were stopped for vehicle defects, such as a burned out headlight or a loud muffler, in 2002 (9.3%), 2005 (9.5%) and 2008 (12.0%). Most drivers pulled over by police believed they were stopped for a legitimate reason An estimated 84.5% of drivers pulled over by police in 2008 felt they had been stopped for a legitimate reason (table 11). More than 80% of stopped drivers in 2002 (84%) and 2005 (86%) also believed police had a legitimate reason for pulling them over in a traffic stop.*** Footnote 3 Findings come from the 2002 and 2005 Contacts between Police and the Public reports. See Methodology.*** In 2008, about 73.8% of black drivers believed police had a legitimate reason for stopping them compared to 86.3% of white and 82.5% of Hispanic drivers. Opinions also varied across reasons for traffic stop. Overall a higher proportion of drivers stopped for speeding (90.0%) believed they were stopped for a legitimate reason compared with those stopped for a vehicle defect (82.6%). These proportions varied by race and Hispanic origin. An estimated 78.7% of black drivers stopped for speeding felt they were pulled over for a legitimate reason, compared to 88.7% of Hispanic and 91.8% of white drivers. Among traffic stops for vehicle defects, black drivers (60.7%) were less likely than Hispanic (84.3%) and white (86.8%) drivers to feel they were pulled over for a legitimate reason. A majority of stopped drivers were issued a traffic ticket An estimated 26.7% of stopped drivers received either a written (17.0%) or verbal (9.7%) warning during the traffic stop (table 12). Police issued a traffic ticket to 55.4% of the drivers and arrested 2.6%. No enforcement action was taken for approximately 15.3% of stopped drivers, meaning they did not receive a verbal or written warning nor were they ticketed or arrested. Police ticketed the majority of drivers stopped for speeding (68.6%), a seat belt violation (70.3%), an illegal lane change (52.7%), or a stop light or stop sign violation (58.4%). By comparison, the majority of drivers stopped during a roadside sobriety check reported having no enforcement action taken (68.5%). Police were equally likely to issue tickets to males (55.9%) and females (54.9%) during a traffic stop (table 13). Males (3.5%) were more likely than females (1.4%) to be arrested following a traffic stop, whereas females were somewhat more likely to receive a written or verbal warning. A greater percentage of black (4.7%) than white (2.4%) drivers were arrested during a traffic stop. Black drivers (58.3%) were somewhat more likely than white drivers (53.1%) to be ticketed during a stop. An equal percentage of Hispanic (2.6%) and white (2.4%) drivers were arrested following a traffic stop, while a greater percentage of Hispanic drivers (62.9%) than white drivers (53.1%) received a ticket. In addition, a greater percentage of white drivers (11.2%) received a verbal warning from police, compared to Hispanic (4.5%) and black (6.0%) drivers. Drivers ages 20 to 29 were more likely than drivers age 50 or older to be ticketed by police during a traffic stop. Drivers ages 20 to 29 (4.4%) were also more likely than drivers ages 40 to 49 (1.5%), 50 to 59 (1.3%), and drivers age 60 or older (1.5%) to be arrested during a traffic stop. Due to sample size limitations, further analysis could not be done on police enforcement actions during traffic stops sorted by reason for stop and drivers' race, sex, and age demographics. About 5% of drivers were searched during traffic stops During a traffic stop, police sometimes conducted a search for illicit drugs, open containers of alcohol, stolen property, or other evidence of criminal wrongdoing. In about 5% (870,000) of the traffic stops documented in the 2008 PPCS, police conducted a search of the driver, the vehicle, or both (table 14). The 2008 PPCS data show that * Police were more likely to conduct a search of the vehicle or driver in traffic stops with male drivers (7.4%) than female drivers (1.6%). * Black drivers (12.3%) were about three times as likely as white drivers (3.9%) and about two times as likely as Hispanic drivers (5.8%) to be searched during a traffic stop. * Drivers ages 20 to 29 (9.0%) were more likely than drivers ages 30 to 39 (4.5%), 40 to 49 (2.5%), or 50 to 59 (2.5%), and drivers 60 or older (1.6%) to be physically searched or have their vehicle searched. The 2002 and 2005 surveys also found that about 5% of stopped drivers were searched by police during the traffic stop. Among drivers stopped by police in 2002 and 2005, males were more likely than females and blacks and Hispanics were more likely than whites to be searched during a traffic stop. About 1 out of 10 searches conducted during traffic stops uncovered illegal items Among the estimated 870,000 searches of the driver, vehicle, or both in 2008, about 187,000 were searches only of the driver, 226,000 were searches only of the vehicle, and 458,000 were searches of both the driver and the vehicle (table 15). An estimated 57.7% of driver-only (driver physically searched, frisked, or patted down by police) and 60.0% of vehicle-only searches were consent searches. About 50.8% of searches of both the driver and vehicle were conducted with consent. Consent searches occured because either the officer asks permission to perform a search and the driver then granted it, or the driver volunteered to allow the officer to conduct a search. Searches conducted without consent may occur because the police officer fails to ask permission before conducting the search, the officer asks but the driver refuses, or the search is conducted as a result of an arrest. Among drivers searched and arrested during a traffic stop, about 42.8% were searched after the arrest, and 57.2% were searched before the arrest (not shown in table). An estimated 2.1% of driver-only searches and 1.6% of vehicle-only searches conducted in 2008 discovered evidence of criminal behavior (e.g., drugs, illegal weapons, open containers of alcohol, or other illegal items). When both the driver and vehicle were searched, evidence was uncovered about 14.3% of the time. Evidence was discovered in an estimated 8.4% of searches of a vehicle, driver, or both (not shown in table). No comparisons of the number of searches that yielded criminal evidence were made between drivers of different gender, age, and race categories, as many of the samples on which the separate categories were based were too small to form reliable estimates. Approximately 1 out of 5 drivers (20.7%) who had only their vehicle searched believed police had a legitimate reason to do so. An estimated 36.1% of drivers who had only their person searched and 21.7% of individuals who had both their person and vehicle searched indicated that police had a legitimate reason to do so. Most searches conducted during a traffic stop occurred at night Overall, a larger percentage of traffic stops documented in the 2008 PPCS occurred during the day (67.3%) (6 a.m. to 6 p.m.) than at night (32.7%) (6 p.m. to 6 a.m.) (table 16). However, a majority of traffic stops involving a search (59.7%) or an arrest (68.1%) occurred at night. Among drivers who experienced the use or threat of force by police during a traffic stop, the percentage of stops that occurred at night (60.5%) was slightly larger than the percentage of daytime stops (39.5%). Males, blacks and younger persons were more likely to have a contact with police in 2008 that resulted in the use of force An estimated 776,000 persons experienced force or the threat of force by police at least once in 2008 (table 17). This total represented an estimated 1.9% of the approximately 40.0 million people experiencing face-to-face police contact during 2008. The 2008 PPCS included detailed questions about use-of-force incidents, including the types of force police might have used and whether the respondent thought the amount of force used or threatened was excessive. Respondents who reported more than one contact during 2008 were asked about the use or threat of force by police during their most recent contact that year. During 2008, about 574,000 persons age 16 or older had force used or threatened against them during their most recent contact with police (table 18). This estimate represents about 1.4% of those persons who reported faceto- face contact with police in 2008. The difference between the percentages of contacts involving police use of force in 2002 (1.5%), 2005 (1.6%), and 2008 (1.4%) were not statistically significant. Males were more likely than females to have force used or threatened against them during their most recent contact with police during 2002, 2005, and 2008. Blacks were more likely than whites or Hispanics to experience use or threat of force in 2008. In 2002 and 2005, blacks and Hispanics were more likely than whites to experience the use or threat of force during contact with police. Individuals between the ages of 16 and 29 were more likely than those age 30 or older to experience contact that resulted in force or the threat of force in 2002, 2005, and 2008. Due to sample size limitations, analysis could not be done on the likelihood of experiencing force according to the reason for the contact and race, sex, and age differences. Most persons who experienced force felt it was excessive Residents who experienced a police contact that involved force were asked if they felt any of the physical force used or threatened against them was excessive. The PPCS did not define excessive for the respondent. Most (74.3% or about 417,000) people whose most recent contact with police in 2008 involved force or the threat of force thought those actions were excessive (table 19). Among persons who had a contact that involved force or the threat of force in 2008, no differences were found in the percentage of white, black, and Hispanic individuals who described the incident as excessive. More than half of police use-of-force incidents involved the police pushing or grabbing the individual Survey respondents who said they experienced the use or threat of force by police in 2008 were asked to describe the incident. Some respondents reported that more than one tyhad force used or threatened against them, an estimated 76.6% reported that police threatened to use force during the incident (table 20). An estimated 75.5% of police-use-of force incidents involved the officer or officers shouting at the respondent. About half (53.5%) of the police-use-of-force cases involved the respondent being pushed or grabbed by police. About 1 out of 4 (25.6%) respondents who reported that force was used or threatened during the contact said police pointed a gun at them. Among persons who experienced the use or threat of force by police and characterized it as excessive, about 60% were pushed or grabbed by police. The police kicked or hit the respondent during an estimated 17.2% of incidents involving the threat or use of excessive force. Overall, about 3 out of 4 (74.3%) persons who experienced the use or threat of force in 2008 felt it was excessive (table 21). Among those persons involved in situations in which force was actually applied by police (e.g., grabbing, hitting, using chemical spray, or pointing a gun), an estimated 80.6% believed the actions were excessive. Of respondents who reported that police only threatened force during the incident, about 74% felt it was excessive. Among individuals who reported the use or threat of force only involved police shouting or cursing at them, 42.9% felt that those actions were excessive. Individuals who had contact with police were asked about their behavior during the incident. Among persons experiencing police use or threat of force in 2008, an estimated 21.9% reported that they argued with, cursed at, insulted, or verbally threatened the police (table 22). An estimated 11.6% of those involved in a force incident reported disobeying or interfering with the police. About 5% resisted being handcuffed, arrested, or searched by police. Persons police suspected of wrongdoing or who had contact through a criminal investigation represented a relatively large percentage of the force incidents. Individuals police suspected of wrongdoing accounted for 16.6% of the force incidents compared to 2.5% of all contacts (table 23). Persons whose contact occurred during a criminal investigation accounted for 21.6% of force incidents, compared to 5.6% of all contacts. In 2008, 9.6% of persons who were suspected of wrongdoing by police experienced the use or threat of force (table 24). By comparison, persons who contacted police to report a crime or another problem experienced force or the threat of force less than 1% of the time. More than half of persons who had force used or threatened against them were searched by police About 57% of those who had force used or threatened against them by police were searched either before or after the force occurred (table 25). An estimated 10.4% of persons who experienced the use or threat of force reported that police found illegal items, such as drugs or a weapon (not in table). Among individuals who had force used against them in 2008, an estimated 54.3% were handcuffed and 39.9% were arrested during the incident. The higher percentage of persons handcuffed versus those arrested during force incidents may be an indication that police sometimes used handcuffs to detain people during contact and later released them without making an arrest. Overall, 18.9% of persons who experienced force in 2008 were injured during the incident (not in table). An estimated 83.9% of individuals who experienced force or the threat of force felt that the police acted improperly. Of those who experienced the use or threat of force in 2008 and felt the police acted improperly, 13.7% filed a complaint against the police. Methodology Data collection The National Crime Victimization Survey (NCVS) is an annual survey that collects data on crime against persons age 12 or older from a nationally representative, stratified, multistage cluster sample of U.S. households. Since 1999, the Police-Public Contact Survey (PPCS) has been administered every 3 years as a supplemental survey to all persons ages 16 or older within households sampled for the NCVS. (For more details on the NCVS, see Survey Methodology for Criminal Victimization in the United States, 2007 at www.bjs.gov.) The U.S. Census Bureau fielded the 2008 PPCS questionnaire, processed the survey data, and provided estimation specifications. The 2008 PPCS was pretested in the spring of 2008 and conducted between July 1, 2008, and December 31, 2008. Respondents were asked about their contacts with police during the past 12 months. For instance, persons interviewed in July 2008 were asked about contacts that occurred between August 2007 and July 2008. Those interviewed in August 2008 were asked about contacts between September 2007 and August 2008. In 2008 the PPCS interviewed 57,978 of the 72,566 eligible individuals in the NCVS sample (table 26). Among the PPCS interviews, 22,301 (38.5%) were conducted in person and 35,677 (61.5%) were by telephone. A total of 14,588 nonrespondents who were excluded from the 2008 PPCS as non-interviews or as proxy interviews. Non-interviews (12,803) included respondents not available for the interview, those who refused to participate, and non-English speaking respondents. (Unlike the NCVS interviews, PPCS interviews are conducted only in English.) The remaining 1,785 were proxy interviews representing household members who were unable to participate for physical, mental, or other reasons. After adjustment for nonresponse, the sample cases in 2008 were weighted to produce a national population estimate of 236,511,832 persons age 16 or older (table 27). PPCS nonrespondents consisted of persons whose household did not respond to the NCVS (NCVS household nonresponse), persons within an interviewed NCVS household who did not respond to the NCVS (NCVS person nonresponse), and persons who responded to the NCVS but did not complete the PPCS (PPCS person nonresponse). The NCVS household response rate between July and December 2008 was 91%. The NCVS person response rate was 88%, and the PPCS person response rate was 91%. The combined NCVS and PPCS person response rate was 80%. The overall weighted response rate for the 2008 PPCS (calculated by multiplying the household response rate by the combined NCVS-PPCS person response rate) was 73%. To produce national estimates on police-public contacts, sample weights were applied to the survey data so that the respondents represented the entire population, including the nonrespondents. Despite the nonresponse adjustments, low overall response rates and response rates to particular survey items can still increase variance in these estimates and produce bias when the nonrespondents have characteristics that differ from the respondents. The Office of Management and Budget (OMB) guidelines require a nonresponse bias study when the overall response rate is below 80%. BJS and the Census Bureau compared the distributions of respondents and nonrespondents and nonresponse estimates for various household and demographic characteristics, and examined their impact on the national estimates produced for the 2008 PPCS. The study looked at household-level and person-level response rates and found no significant variation or bias in the rates among various population groups. The largest bias among the household characteristics was in region and type of location in urban areas; however, these biases were reduced in the nonresponse adjustments. The largest bias in person nonresponse was observed in the Hispanic origin characteristics. Nonresponse statistics were also computed for key survey questions from the PPCS, and no evidence of bias was found during the analysis. Follow-up interviews PPCS respondents were asked about their contact with police during the 12 months prior to their interview. Persons who said they had a face-to-face contact during 2008 were asked to describe the nature of the contact. Persons who had more than one contact were asked about only their most recent contact during the time period. Respondents were provided a list of six specific reasons for having contact with police: 1) traffic accident, 2) traffic stop, 3) reporting a crime, 4) police provided assistance, 5) police investigating crime, and 6) the police suspected the resident of wrongdoing. Respondents who reported having contact during a traffic stop were asked whether they were the driver or passenger in the vehicle. Drivers were asked an additional set of questions about the reason for being pulled over and the actions taken by police during the stop. A seventh category allowed interviewers to record reasons that did not fall into any of the six specific reasons. Among the 9,549 respondents who had contact with police, 751 reported the reason for contact under this nonspecific category. Following the data collection, BJS examined these write-in responses to determine if any descriptions fit one of the six categories and, when possible, coded the field into an existing category. This review uncovered 302 responses that indicated the reason for contact was related to a traffic stop. Some of these records lacked sufficient detail to determine whether the respondent was a driver or passenger in a vehicle that had been pulled over by police or was reporting some other type of contact that was connected to a traffic stop (e.g., paying a speeding ticket). Stopped drivers who were not originally classified under the specific category during the interview did not receive the additional questions about the traffic stop. To address this potential missing data issue, BJS instructed the Census Bureau to conduct follow-up interviews with 122 of these respondents to seek clarification on the nature of their contact with police. Ninety respondents agreed to complete the follow-up interview. Of the completed interviews, 79 respondents reported that their contact with police occurred as a driver in a traffic stop and completed the additional set of questions regarding the traffic stop. Limitations of the estimates BJS administers the PPCS questionnaire to all persons age 16 or older who reside in U.S. households sampled for the NCVS. The PPCS excludes proxy interviews for a person unable to participate because of physical, mental, or other reasons. BJS staff determined that caregivers and other proxy interviewees would have difficulty describing the details of any contacts with police and decided to exclude them. To the extent that persons who experience contacts with police do not fall into this target population, the PPCS data collection missed certain encounters between the law enforcement officers and members of the public. For instance, this household survey did not interview U.S. residents living abroad, homeless persons, or persons living in military barracks. The PPCS also did not interview persons institutionalized (e.g., incarcerated in a correctional facility) at the time of the interview about their encounters with police during the 12-month reference period. Such exclusions may affect the findings because contact with police leading to incarceration would involve more serious outomes (e.g., contacts involving an arrest or use of force by police). The BJS Survey of Inmates in Local Jails (SILJ) collects data from a nationally representative sample of jail inmates on a wide range of topics, including the specific types of force police might have used or threatened to use during the arrest that preceded the inmates' incarceration. An analysis of the 2002 SILJ and 2002 PPCS data found that the percentage of inmates who experienced the use or threat of force at the time of their arrest was about 22%, while the percentage of PPCS respondents who had a contact with police that involved force or the threat of force was about 1.5%. *** Footnote 4 See Hickman, M., Piquero, A., & Garner, J. (2008). Toward a national estimate of police use of nonlethal force. Criminology & Public Policy. *** When combining the PPCS and SILJ data, the overall estimated percentage of contacts that involved the threat or use of force in 2002 was 1.7%. This report describes the prevalence of public contact with the police and the prevalence with which the contact involves traffic stops, searches, and uses of force. It describes the extent to which prevalence rates vary by some of the categories of respondent characteristics or by the nature of the contact. This information is collected and disseminated to inform the public about the nature of interaction between law enforcement officers and the public. However, the data collected and described in this report cannot provide a sufficient basis to infer a causal relationship between characteristics of the respondent and behavior of police. This limitation exists despite the descriptive statistics that seem to show some differences (or no differences) in the prevalence of contacts, stops, searches, or use of force in relationship to the age, race, or sex of the respondent. Conducting tests of statistical significance Persons interviewed through the PPCS sample have a known probability of selection, and their responses can be used to produce national estimates of contacts between police and the public. Since the estimates are based on a sample of the population and not a complete enumeration, these estimates are subject to sampling error (a discrepancy between an estimate and a population parameter based on chance). Sampling error varies by the size of the estimate in relation to the size of the base population, and is reduced by increasing the size of the sample taken from the population. A standard error is a measure of the sampling error, or the margin of error due to sampling, and can be used as a measure of precision expected from a sample; the smaller the standard error, the more precise or reliable the estimate. Standard errors for selected tables are available at the end of this report. In general, when comparing estimates between groups, if the difference between two estimates is at least twice the standard error of that difference, there is at least 95% confidence that the two estimates actually differ. Thus, one can conclude that there is a statistically significant difference between the two groups. All differences discussed in this report were statistically significant at or above the 95% confidence interval unless otherwise indicated. Some differences were not significant at the 95% confidence level, but were significant at the 90% level. The report also indicates that some comparisons were not different, which meant that the difference between the two estimates was not significant at either the 95% or 90% levels. In order to calculate the confidence intervals for the estimated 16.9% of residents who had contact with police in 2008, the calculated standard error of 0.3% was used (appendix table 5). The 95% confidence interval around this estimate was calculated as plus or minus 1.96 multiplied by 0.3% (or 16.3% to 17.6%). The 95% confidence interval around the percentage of residents who had contact in 2005 was 19.1% plus or minus 1.96 multiplied by 0.5% (or 18.2% to 20.1%). Statistical significance tests found that the difference between these two estimates was statistically significant at the 95% confidence level. This means the apparent difference was not simply the result of surveying a sample rather than the entire population. Significance testing calculations were conducted using statistical programs developed specifically for the PPCS by the U.S. Census Bureau. These programs take into consideration the complex sample design of the PPCS when conducting tests of statistical significance. Comparing estimates from the Police-Public Contact Surveys Certain comparisons were limited in this report to findings from the 2002, 2005, and 2008 surveys for several reasons. Changes were made to the data collection instrument following the 1999 survey to reduce the overall response burden to survey participants. These changes affected estimates of the reasons for contact with police and information on contacts that occurred while driving a vehicle that was stopped by police. In 1999, respondents were asked to identify the reasons for all of their contacts with police during the previous 12 months and the frequency of those contacts. In addition, any respondent who had been pulled over in a traffic stop in the last year was asked to describe the nature and outcome of the stop. Following the 1999 survey, the data collection instrument was changed so that respondents were only asked to provide detailed information on their most recent contact with police during the previous 12 months. Respondents whose most recent face-to-face contact was not a traffic stop, but who had been pulled over by police earlier in the year, were not asked to describe that incident. Following the 1999 survey, the measurement of the number of drivers in the United States was also modified, making the estimate of the likelihood of being stopped by police in 1999 is not directly comparable to estimates in 2002, 2005, and 2008. The denominator used to calculate the likelihood of being stopped by police was "licensed drivers" in 1999, as estimated by the U.S. Department of Transportation's 1995 Nationwide Personal Transportation Survey. In 2002, 2005, and 2008, the denominator was "drivers in the United States," as estimated directly from responses to additional questions included in Police-Public Contact Surveys. The denominator change was made to account for all persons who drive, licensed and not licensed, to better approximate the number of persons at risk of being stopped by police. Excluded from the new denominator were licensed drivers who indicated that they never drive. A number of methodological changes were implemented in the NCVS in 2006. Analyses of the survey data after 2006 indicated that the changes had a relatively small impact on the estimates and that the 2008 estimates are comparable with estimates for 2005. Information on the methodological changes to the NCVS are available online at www.bjs.gov. Some of the 2005 national estimates in this report differ slightly from those shown in the BJS report Contacts between Police and the Public, 2005. The weights for the 2005 PPCS data were revised to reflect a slight change of the NCVS person weights, which were the starting point for the PPCS weights. For instance, the difference between the overall rate of police-public contact from the 2005 report (19.09%) and the revised rate (19.14%) was about 0.05%. Other BJS reports on police-public contact Each of the following publications is available on the BJS website. * Police Use of Force: Collection of National Data, NCJ 165040, November 1997 * Contacts between Police and the Public: Findings from the 1999 National Survey, NCJ 184957, February 2001 * Characteristics of Drivers Stopped by Police, 1999, NCJ 191548, March 2002 * Contacts between Police and the Public: Findings from the 2002 National Survey, NCJ 207845, April 2005 * Characteristics of Drivers Stopped by Police, 2002, NCJ 211471, June 2006 * Contacts between Police and the Public, 2005, NCJ 215243, April 2007 ************************************************ Office of Justice Programs * Innovation * Partnerships * Safer Neighborhoods * http://www.ojp.gov ************************************************ The Bureau of Justice Statistics is the statistical agency of the U.S. Department of Justice. James P. Lynch is the director. This special report was written by Christine Eith and Matthew R. Durose. The U.S. Census Bureau fielded the questionnaire, processed the survey data, and provided estimation specifications. Joseph Swiderski assisted with data processing. Alexia Cooper, Erika Harrell, Sheri Simmons, and Erica Smith verified the report. Catherine Bird and Jill Thomas edited the report, Tina Dorsey and Barbara Quinn produced the report, and Jayne E. Robinson prepared the report for final printing, under the supervision of Doris J. James. October 2011, NCJ 234599 This report in PDF and in ASCII and its related statistical data and tables are available at the website: http://www.bjs.gov/index.cfm?ty=pbdetail&iid=2229. ************************************************ 9/27/2011/ JER/3:15pm