Racial profiling in the criminal justice system

Racial bias in traffic stops and searches
According to Baumgartner, Epp, Shoub [2018]


 * “Blacks are almost twice as likely to be pulled over as whites — even though whites drive more on average,”
 * “blacks are more likely to be searched following a stop,”
 * “just by getting in a car, a black driver has about twice the odds of being pulled over, and about four times the odds of being searched.”

Black and Latino drivers nationally are more likely to be searched once they have been pulled over. Perisco and Todd (2006) analyzed and summarized 15 studies on the hit rate for car searches in various parts in the US.



On average, the white hit rate was 15% higher than the black hit rate and 47% higher than the Hispanic hit rate. In absolute terms, the gap between whites and blacks was 2.45 points while the gap between Hispanics and whites was 6.9 points. The raw data shows that police will pull over Hispanics and blacks slightly more than whites despite having a lower "hit rate".

This disparity could be due to more factors than just racial profiling.


 * Grogger and Ridgeway 2006 analyzed data on 7,607 police stops that took place in Oakland, CA. It found that black people account for a greater proportion of those being pulled over during night hours when the race of the driver would not be visible to police.
 * Smith et al 2001 analyzed data on 2,673 traffic stops that took place in Richmond, Virginia. The probability that someone being pulled over was black did not differ between white and non-white police officers.
 * [[File:Virginiaracism.png]]
 * Baumgartner et al. 2018 analyzed data on 164,322 police stops that took place in Charlotte, NC and found that anti-black bias in police stops was greatest among black police officers.
 * [[File:Ncdataacias.png]]

New York City
The research most often cited by the critics involves “hit rates” or the proportion of those stopped found to be engaging in criminal activity. In a racially biased system the hit rate will be higher for whites. In other words, among those searched, white people will have higher rates of having committed a crime.

The reason for this involves how high the police require the probability of someone being a criminal to be in order to justify stopping or searching them. For instance, if police only search whites when there is evidence that makes it at least 60% likely that they are committing a crime, but requires a lower bar of evidence to search blacks and so will search them if there is only a 40% probability of them committing a crime, then the “hit rate” will be .60 for whites and .40 for blacks. Thus, a higher hit rate for whites implies that police are requiring a higher bar of evidence to search whites than to search blacks.

Anyway, the critics seems particularly preoccupied with pedestrian stops in New York City. According to an article published by Vox which looked at data on New York’s stop and frisk policy, only 1% of stopped blacks are found to be carrying a weapon or contraband compared to 1.4% of stopped whites. Thus, the white hit rate was 40% greater than the black hit rate.



Lopez (2016)

The critics likes to concentrate on Stock and Frisk searches and that is likely because pedestrian stops taken as a whole display less evidence of bias.

Ridgeway (2007) analyzed data on all pedestrian stops the took place within New York City between 2005 and 2006. This included “stop and frisk” encounters as well as others.


 * The paper found that, among those who were stopped, 5.1% of whites and 4.8% of non-whites were arrested. This suggests that hit rate for whites was only 6% greater than the non-white hit rate once all police encounters were taken into account.
 * The paper also found that “black pedestrians were stopped at a rate that is 20 to 30 percent lower than their representation in crime-suspect descriptions.” On the other hand, “Hispanic pedestrians were stopped disproportionately more, by 5 to 10 percent, than their representation among crime-suspect descriptions would predict.” This suggests that if any bias is taking place against non-whites, it is against Hispanics and not blacks.
 * A limitation of this research is that it does not control for variation in the stop and arrest rates of each precinct. Minorities tend to live in precincts with police who are more aggressive in their stop and arrest patterns regardless of race. Once you control for this variation, racial bias in hit rates disappears.

For instance, Coveillo et al. (2015) analyzed data on 2,947,865 police stops in New York City from the years 2003 to 2012 and they found that “after accounting for the fact that different precincts have different baseline rates of arrest conditional on search, African Americans are no longer less likely to be arrested conditional on being stopped”. The same was true of Hispanics.

Boston
Stop and frisk incidents in Boston between 2007 and 2010 that did not result in a citation or arrest found that 63 percent of such stops were of black people. Blacks made up 24 percent of the city’s population. Incredibly, 97.5 percent of these encounters resulted in no arrest or seizure of contraband.

State Data
North Carolina

Blacks and Latinos in North Carolina were more likely to be searched than whites (5.4 percent, 4.1 percent and 3.1 percent, respectively), even though searches of white motorists were more likely than the others to turn up contraband (whites: 32 percent, blacks: 29 percent, Latinos: 19 percent)

New Jersey

Black people in New Jersey were 2.6 to 9.6 times more likely to be arrested than white people for low-level offenses.

City Data
Chicago

In Chicago, black neighborhoods were getting three times more bicycle tickets than white neighborhoods.

Ferguson


 * Between 2012 and 2014, black people in Ferguson, Mo., accounted for 85 percent of vehicle stops, 90 percent of citations and 93 percent of arrests, despite comprising 67 percent of the population.
 * Blacks were more than twice as likely as whites to be searched after traffic stops, even though they proved to be 26 percent less likely to be in possession of illegal drugs or weapons.
 * Between 2011 and 2013, blacks also received 95 percent of jaywalking tickets and 94 percent of tickets for “failure to comply.”
 * The Justice Department also found that the racial discrepancy for speeding tickets increased dramatically when researchers looked at tickets based on only an officer’s word vs. tickets based on objective evidence, such as vs. radar.

United States Department of Justice Civil Rights Division