Are you not familiar with the CPD (Chicago Police Department)? The police probably have more of an impact on the topic at hand (crime and violence) than CPS.
They are far more shameful, dysfunctional, and incompetent than CPS. From forced confessions [1] to planting drugs [2] to electing radical leaders [3]. They are on a Federal consent decree because of their ineptitude and violations of civil rights [4].
[1] https://news.wttw.com/2017/09/22/chicago-really-false-confes...
[2] https://news.wttw.com/2021/11/04/judge-tosses-5-more-convict...
[3] https://chicago.suntimes.com/2022/4/21/23036206/fop-fraterna...