These variables count one stop for each separate individual stopped by an officer. The data includes a number of different stop types, including pedestrian, vehicle stops, terry stops (also known as “stop and frisk”), and searches. The data includes stops reported by the Los Angeles Police Department (LAPD) in LAPD reporting districts within the City of Los Angeles. 

Stops are the most common way that police directly initiate contact with citizens and have been shown to cause harmful trauma to some people stopped. After a stop occurs, there are multiple possible outcomes. Most commonly, nothing happens; however, an arrest, issuance of a citation, or warning are also possible outcomes of a stop. In 2015, the state of California passed AB 953 which mandates that stops data be collected and analyzed across the state to look for racial bias. The LAPD have been collecting and publishing their stops data since 2011, making them unique among large law enforcement agencies in Southern California.

Stops can be influenced by several factors, most of which point to systematic issues within policing.

• Veil of Darkness Effect: The time of day may have an effect on police bias when conducting traffic stops. This “veil of darkness” that occurs after sundown provides immunization against racial profiling for Black drivers, as reported in a study that investigated 95 million traffic stop records over the course of five-years. The study concluded that police officers were less likely to target and pull over Black drivers as the sky darkened throughout the year. Due to this effect, some jurisdictions are currently attempting to limit minor stops to reduce these potentially racially biased interactions. The Los Angeles Police Department has changed its practices as a result of a larger investigation conducted by the Los Angeles Times.
• Quotas: Another facet that influences bias is minimum quotas set forth by police departments. Although this practice is illegal in California, police officers have faced punishment and retribution for not meeting daily “production goals.” Quotas incentivize law enforcement to forgo focusing on public safety and instead chase numbers to secure promotions. In 2013, the City of Los Angeles agreed to a $6 million settlement to police officers who claim they were punished for failing to meet their goals.
• Selection Bias: Similar to crime metrics, traffic stops may not be an accurate measure of a community’s public safety. Selection bias occurs when crime statistics are based on reported crime data that may be overrepresentation of certain areas. Increased policing in low-income neighborhoods, compared to smaller police presences in affluent neighborhoods, could result in statistics skewing towards the presumption that low-income neighborhoods are prone to higher rates of crime.

Written by Caroline Ghanbary