Hundreds. You may be surprised to learn this, but shooters and killers often violently resist being arrested unless they face clearly overwhelming force. A lot of murderers and shooters have been peacefully arrested by CPD tactical officers.

You can see the use of force incidents that resulted in complaints here, on the Civilian Office of Police Accountability case portal [0] (although not all of these involve tac officers). You can also see the statistics on rates of use of force in this dashboard [1], and see what counts as use of force (as well as when use of deadly force is authorized) here [2].

It's important that people actually check up on their police departments. Police serve a vital and life-saving role in society, but they have to be actually monitored. Just assuming they're all bad gives cover to the bad ones and discourages good ones from signing up, and as someone who checks, I can tell you that the people most abused by America disproportionately call the police for help, and many of their emergencies are truly harrowing.

[0] https://www.chicagocopa.org/data-cases/case-portal/

[1] https://home.chicagopolice.org/statistics-data/data-dashboar...

[2] https://home.chicagopolice.org/wp-content/uploads/2017/05/G0...