Gangs of Chicago, through police's flawed lens

BY Matt Rehbein

Published August 2, 2018

Just over a month ago, a half dozen activist groups and four men sued the city of Chicago, its police department and various public officials over law enforcement's use of a database designed to track members of criminal gangs.

The federal class action lawsuit decries Chicago police's gang database as "arbitrary, discriminatory, over-inclusive, and error-ridden." The four named plaintiffs deny being gang members and argue that their inclusion in the database has hurt their job prospects and led to harassment from police.

The Chicago police department released scrubbed versions of its gang database in November and again in March, according to ProPublica, which offers a free download of the database via its data store.

Analysis of the released information corroborates much of what the lawsuit and other critics have alleged.

Racially and ethnically lopsided

The data released by the Chicago police include more than 128,000 suspected gang members. About 70% of those individuals are black, 25% are hispanic ("white hispanic," as categorized in the database) and about 4% are white.

The two charts below show how the racial and ethnic divides in the police database compare to Chicago's overall demographics. (Note that categories of race in the police database differ slightly from racial and ethnic categories defined by the US Census Bureau.)

Racial and ethnic breakdown of Chicago

White     Black    Hispanic    Asian    Multiracial    Native Amer    Pacific Islander

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Racial and ethnic breakdown of alleged gang members

Black   Hispanic   White   Black Hispanic   Asian/Pacific Islander   Unknown   Native Amer

graph city pop changes
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SOURCES: US Census Bureau (left); Chicago Police Dept via ProPublica (right)

The class action lawsuit argues that the police database "under-counts white gang members" by largely ignoring white supremacist groups and omitting biker gangs all together.

It's unclear judging from only the names of the gangs listed whether biker gangs have been entirely excluded, but majority-white gangs account for a small portion in the police tally.

According to the database, black and hispanic members make up overwhelming majorities of the city's biggest gangs.

Racial and ethnic breakdown of ten biggest gangs in CPD database

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SOURCE: Chicago Police Dept via ProPublica

By comparison, the ten gangs with the largest percentages of white members make up just under a thousand of the tens of thousands of suspected gang members in the database.

Racial and ethnic breakdown of biggest white-majority gangs in CPD database

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NOTE: For clarity, two database entries with apparent typos have been combined with entries of the same name. For example, an entry under "White Supremist" was added to the group "White Supremacist."
SOURCE: Chicago Police Dept via ProPublica

Last week Chicago Inspector General Joe Ferguson said his office is producing two reports about the CPD database, the first of which will be released by the end of the year, according to the Chicago Sun-Times.

In April a CPD spokesman told ProPublica that the department was working on a plan to clarify guidelines for adding names to the gang database. The plan will also address which other law enforcement agencies have access to the database, as well as how individuals can seek to have their names removed from it, the spokesman said.