The data is controversial. Activists say that too many young people are misidentified as gang members and are forced to carry that designation all through their lives. But police defend the data, saying it assists them in fighting the war against gangs, who have unleashed an unprecedented level of violence in the city.

Police data obtained by the Chicago Tribune after an open records request shows that almost 33,000 Chicago juveniles have been arrested over the past two decades and identified as gang members.

The records released to the Tribune through a Freedom of Information Act request included 20 years of arrest data in all for adults as well as juveniles, giving a glimpse at how the department gathers and stores information on the tens of thousands it says have been gang-affiliated. It’s a controversial practice that has led to an ongoing audit by the city’s Office of Inspector General, a federal lawsuit against the city and a proposed city ordinance to limit its impact. Critics and experts say that the gang labels are often too easily attached, racially skewed and out of date, yet the harm can be lasting when the Police Department shares flawed gang intelligence with other law enforcement agencies such as immigration officials. It can also be a damaging label during criminal investigations or at sentencings. While the department released adult gang records to the newspaper in April, it had refused to provide similar data on juveniles, citing privacy laws. After the Tribune appealed to the Illinois attorney general’s office for the juvenile records, though, the department’s Bureau of Technical Services released a new set of data. The department said its most recent search took a more thorough look at arrest data, but it still didn’t capture everyone labeled a gang member by Chicago police because it excluded street stops that didn’t result in arrests. That means the department could have far more than 33,000 juveniles listed as gang members in its databases.

Gang members are usually members for life - or death - so the value of this database should be immediately clear to anyone concerned about gang violence. Tracking the rise of juvenile offenders to gang kingpins makes it easier to track offenders, gather intelligence, and arrest perpetrators.

There are almost certainly mistakes in the database. But anyone who has been misidentified is not likely to lose employment or be denied entrance to a school because the data isn't publicly available. Only if someone is suspected of committing a crime will the database be employed.

The point being, there are very few "innocent" people in that database. If you avoid getting arrested, the records won't come into play.

The idea that the data is "racially skewed" is absurd. Nothing is skewed when the arrests or police stops occur in neighborhoods where there a few to no white faces. Bringing up race is a typical distraction used by activists that makes it appear as if they want to obstruct the police in their efforts to crack down on gangs.

It's frightening to contemplate that despite the database, gang violence is way out of control, making the city a shooting