Police Stops and Searches 

There are three distinct parts of the criminal legal system: police, courts, and corrections. Police are considered the gatekeepers to the criminal legal system because the decisions they make largely determine if and how much a person will interact with the rest of the system.[1]  In 2015 and 2018, traffic stops were the most common reason for contact with the police that was initiated by the police.[2] The decision to make a traffic stop and the subsequent decision to search the person and/or vehicle are important to examine when considering equity.  As it relates to traffic stops across the country, research is consistent that Black and Hispanic people are stopped disproportionately, men are stopped more frequently than women, and Black men are more likely to be searched once stopped. [3],[4] These findings are so pervasive for Black drivers that the phenomenon has been labeled “Driving While Black.”[5] Although research on racial disparities is consistent, current methods limit the ability to draw causal inferences. 
 
To assess whether groups of people are disproportionately stopped by police, this report compares the number of stops within a demographic group to the number of people within that group who are available to be stopped.[6] Estimating the number of people available to be stopped within an area is difficult because population estimates include people that do not drive and there are an unknown number of drivers passing through areas they do not live in. Some researchers estimate the number of people available to be stopped as the number of residents over a certain age.[7],[8],[9] Another option, used in this report, is to estimate the number of drivers in traffic collisions. This includes either at-fault drivers, not-at-fault drivers, or both. Using any subset of drivers in traffic collisions provides a snapshot of the people who are actually driving in a given jurisdiction.
 
Data on the traffic stops and searches in 2021 were obtained from the Racial and Identity Profiling Act (RIPA) Stop Data, collected by the California Department of Justice and available on the OpenJustice data portal.[10] Traffic collision data were obtained through the Statewide Integrated Traffic Records System for collisions that occurred January 1, 2021, to December 31, 2021.[11]  The RIPA Stop Data program started with requiring only the largest police departments to report their stop data to the state In 2021 three police departments in San Diego County were large enough to meet the reporting requirements: the Carlsbad Police Department, the San Diego Police Department, and the San Diego County Sheriff’s Department. The San Diego Sheriff’s Department is responsible for patrolling the unincorporated areas of the county as well as the cities of Del Mar, Encinitas, Imperial Beach, Lemon Grove, Poway, San Marcos, Santee, Solana Beach, and Vista. All departments are required to report traffic stop data to the California Department of Justice by 2023.
 
The California Code of Regulation defines a stop as “(1) any detention…by a peace officer of a person; or (2) any peace officer interaction with a person in which the officer conducts a search.”[12] Analyses were limited to stops for traffic violations, which included moving violations, equipment violations, and non-moving violations. It is not possible to differentiate between drivers and passengers in the RIPA stop data; therefore, these data show the number of stops, not the number of people present for the stop. Demographic information reported in the RIPA data, including race/ethnicity, gender, age, LGBT status, etc., are based on the perception of the police officer and are not self-identified by those stopped. Demographic information reported from the traffic collision data include some self-reported characteristics and some characteristics reported by the responding officer based on officer perception. [13]
Figures 1-6 display the discrepancy between the actual number of traffic stops and the expected number of traffic stops if the number of stops was proportional to the number of at-fault drivers involved in traffic collisions in each jurisdiction. In the cities of Carlsbad (Figure 1) and San Diego (Figure 3), Black, and Hispanic people were overrepresented in traffic stops because those groups experienced a greater number of stops than traffic collisions in 2021. White people were underrepresented in traffic stops compared to at-fault White drivers in traffic collisions in those cities. In contrast, in the San Diego County Sheriff’s jurisdiction (Figure 5), White people were overrepresented in traffic stops in 2021, while Black/African American and Hispanic/Latino people were underrepresented in traffic stops. The San Diego Police Department and San Diego County Sheriff’s Office stopped those classified as some other race more frequently than expected and across all three jurisdictions Asian people were stopped more frequently than expected. In both Carlsbad (Figure 2) and the City of San Diego (Figure 4), men were overrepresented in traffic stops and women were underrepresented compared to what may be expected based on the number of traffic collisions. The opposite pattern was observed within the San Diego County Sheriff’s jurisdiction (Figure 6), men were underrepresented and women were overrepresented in traffic stops.
Carlsbad Police Department, 2021: Actual and Expected Traffic Stops
Figure 1. Actual and Expected Traffic Stops by Race/Ethnicity, Carlsbad Police Department, 2021
Figure 2. Actual and Expected Traffic Stops by Sex, Carlsbad Police Department, 2021                
San Diego Police Department, 2021: Actual and Expected Traffic Stops
Figure 3. Actual and Expected Traffic Stops by Race/Ethnicity, San Diego Police Department, 2021
Figure 4. Actual and Expected Traffic Stops by Sex, San Diego Police Department, 2021            
San Diego County Sheriff's Department, 2021: Actual and Expected Traffic Stops
Figure 5. Actual and Expected Traffic Stops by Race/Ethnicity, San Diego County Sheriff's Department, 2021
Figure 6. Actual and Expected Traffic Stops by Sex, San Diego County Sheriff's Department, 2021  

The percentage of at-fault drivers (Figures 7 and 8) and the disproportionality index (Figures 9 and 10) by race/ethnicity and gender are shown for each jurisdiction. The disproportionality index is another way of looking at possible inequities in traffic stops and was calculated by dividing the rate of stops by the rate of at-fault drivers in collisions. Disproportionality index values over one indicate that a group was overrepresented in traffic stops compared to the population of at-fault drivers on the road. Values under one indicate that a group was underrepresented in stops to the population of at-fault drivers on the road. The patterns observed in the disproportionality index data are the same as those observed in the figures above.
Figure 7. Percentage of At-Fault Drivers by Race/Ethnicity and Jurisdiction, 2021
Figure 8. Percentage of At-Fault Drivers by Sex and Jurisdiction, 2021

Figure 9. Disproportionality Index by Race/Ethnicity and Jurisdiction, 2021
Figure 10. Disproportionality Index by Sex and Jurisdiction, 2021
Figures 11-16 present data related to searches requested during traffic stops in San Diego County in 2021 for each of the three agencies. As searches tend to be another high discretion event, the figures present the percentage of people in each racial/ethnic group and gender for which officers requested a search. Searches could be requested of the person, property, or both. This type of search is often referred to as a “consent search,” as opposed to a search where the officer sees evidence that justifies a search without consent. Requests for consent searches were a rare event in all three departments, occurring in less than 4% of all traffic stops.
Carlsbad Police Department, 2021: Percent of Searches Requested 
Figure 11. Percent of Searches Requested by Race/Ethnicity and Type of Search, Carlsbad Police Department, 2021
Figure 12. Percent of Searches Requested by Sex and Type of Search, Carlsbad Police Department, 2021              
San Diego Police Department, 2021: Percent of Searches Requested 
Figure 13. Percent of Searches Requested by Race/Ethnicity and Type of Search, San Diego Police Department, 2021
Figure 14. Percent of Searches Requested by Sex and Type of Search, San Diego Police Department, 2021            
San Diego County Sheriff's Department, 2021: Percent of Searches Requested
Figure 15. Percent of Searches Requested by Race/Ethnicity and Type of Search, County Sheriff, 2021
Figure 16. Percent of Searches Requested by Sex and Type of Search, County Sheriff, 2021

Figures 17-20 provide the percentage of searches that were actually conducted and a hit rate equal to the number of times contraband was discovered over the total number of searches conducted in 2021. In the City of San Diego, the hit rate for police finding contraband in a traffic search was similar across all groups: between 34% and 40% of searches yielded contraband or evidence. However, Black/African American people were searched at much higher rates than others in the City of San Diego: 17% of Black/African American people who were stopped were searched compared to about 6% of White people. Though White people were searched less frequently than their Black/African American and Hispanic/Latino counterparts, they were more likely to be found to have contraband or evidence across the three jurisdictions. Hispanic/Latino people were searched among the highest rates but had among the lowest rate of carrying contraband. Across all jurisdictions men were searched more frequently than women, though for San Diego PD and San Diego County Sheriff’s office women had higher hit rates than their male counterparts.
Figure 17. Hit Rates by Race/Ethnicity and Jurisdiction, 2021
Figure 18. Hit Rates by Sex and Jurisdiction, 2021
Figure 19. Percent of Searches Conducted by Race/Ethnicity and Jurisdiction, 2021
Figure 20. Percent of Searches Conducted by Sex and Jurisdiction, 2021

Data Information
Data Sources: Racial and Identity Profiling Act Stop Data, 2021 and California Highway Patrol Collision Data, 2021.
  • For Carlsbad Police Department, 68 (15%) collisions were missing data on race/ethnicity and 61 (13%) were missing data on gender; these cases were removed from analyses. Vehicle passengers were present during 85 (2.5%) of the traffic stops.
  • For San Diego Police Department, 564 (18%) collisions were missing data on race/ethnicity and 363 (11%) were missing data on gender; these cases were removed from analyses. Vehicle passengers were present during 4,091 (6.2%) of the traffic stops.
  • For the San Diego County Sheriff's Department, 176 (11%) collisions were missing data on race/ethnicity and 113 (0.07%) were missing data on gender; these cases were removed from analyses. Vehicle passengers were present during 332 cases (1.9%) of the traffic stops.
  • Data were suppressed if incidence was less than 5. 
References
  1. Neusteter, R.S., Subramanian, R., Trone, J., Khogali, M., & Reed, Cindy. (2019). Gatekeepers: The Role of Police in Ending Mass Incarceration. Vera Institute of Justice. Retrieved from https://www.us-amsa.org/wp-content/uploads/2021/08/VERA-Gatekeepers-Report.pdf
  2. Harrell, E., & Davis, E. (2020). Contacts between police and the public, 2018 – Statistical tables (NCJ 255730). Bureau of Justice Statistics. Retrieved from https://bjs.ojp.gov/content/pub/pdf/cbpp18st.pdf
  3. Farrell, A. (2015). Explaining leniency: Organizational predictors of the differential treatment of men and women in traffic stops. Crime & Delinquency, 61(4), 509–537. https//doi.org/10.1177/0011128711420108    
  4. Smith, M. R., Rojek, J. J., Petrocelli, M., & Withrow, B. (2017). Measuring disparities in police activities: A state of the art review. Policing: An International Journal of Police Strategies & Management, 40(2), 166–183. https://doi.org/10.1108/PIJPSM-06-2016-0074
  5. Ibid.
  6. Ibid.
  7. Ibid.
  8. Alpert, G. P., Dunham, R. G., & Smith, M. R. (2007). Investigating racial profiling by the Miami-Dade police department: A multimethod approach. Criminology & Public Policy, 6(1), 25–55. https://doi.org/10.1111/j.1745-9133.2007.00420.x
  9. Smith, M. R., Tillyer, R., Lloyd, C., & Petrocelli, M. (2021). Benchmarking disparities in police stops: A comparative application of 2nd and 3rd generation techniques. Justice Quarterly, 38(3), 513–536. https://doi.org/10.1080/07418825.2019.1660395
  10. State of California Department of Justice—OpenJustice. (2023). Retrieved February 24, 2023, from https://openjustice.doj.ca.gov/data
  11. California Highway Patrol. (2019). Statewide Integrated Traffic Records System. Retrieved February 24, 2023, from https://iswitrs.chp.ca.gov/Reports/jsp/userLogin.do
  12. California Code of Regulations; Title 11, Law; Division 1, Enforcement; Chapter 19, Final Text of Regulations. Retrieved from https://oag.ca.gov/sites/all/files/agweb/pdfs/ripa/stop-data-reg-final-text-110717.pdf  
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Updated February 7, 2024