Why is the Boston Police targeting black & brown people?

The Boston Police Department (BPD) has used racially biased policing, as shown by data from reports of 200,000+ encounters between BPD officers and civilians from 2007–2010. According to researchers, the data show that police targeted Blacks in 63.3% of encounters—while Blacks make up less than a quarter of Boston's population.
This racial disparity cannot be explained away by BPD efforts to target crime. The researchers' preliminary statistical analysis found that the racial composition of Boston neighborhoods drove police-civilian encounters even after controlling for crime rates and other factors. They also found that Blacks were more likely than whites to be subjected to repeat police-civilian encounters and to be frisked or searched, even after controlling for civilians' alleged gang involvement and history of prior arrest.
Click here to read the ACLU report "Black, Brown & Targeted'.
The bottom line is that race was a significant factor driving the BPD's stop-and-frisk practices.

• 63% of Boston police-civilian encounters from 2007-2010 targeted Blacks, even though Blacks made up less than 25% of the city's population
• Even after controlling from crime, Boston police officers were more likely to initiate police encounters in Black neighborhoods and to initiate encounters with Black people
• Boston police gave essentially no justification for 75% of these encounters, simply listing "investigate person" as the reason
• More than 200,000 encounters led to no arrest, and only 2.5% led to seizure of contraband
https://www.aclum.org/stopandfrisk
Boston police data shows widespread racial bias in street encounters with civilians
ACLU of Massachusetts media release
Boston Police Have a Racially Biased Policing Problem, and a Golden Opportunity to Reform
ACLU blog
ACLU study finds blacks disproportionately targeted by police stop-and-frisks
Bay State Banner
New study: Only 24% of population, blacks in Boston make up 63% of stop and frisk encounters
The Washington Post
ACLU blasts BPD over huge ‘stop and frisk’ racial disparities
Boston Herald
The Staggering Racial Disparity In Boston's Police Encounters
The Huffington Post
Boston police engaged in racially biased tactics, ACLU says
Boston Globe
ACLU Finds 'Racial Bias' In Boston Police Encounters
WBUR