It is disheartening that you appear to be so willing to go along with with whatever police do all in the name of safety. Do you really view the world in such a way that you can’t comprehend having a police force that does it’s job without beating suspects who are already in custody?
https://chicago.suntimes.com/2021/2/3/22263444/new-chicago-p...
Note that Burge was arrested for lying to a jury during a civil lawsuit not for torture.
In most states, anybody can use force to arrest criminals,
https://en.wikipedia.org/wiki/Citizen%27s_arrest#United_Stat...
Of course the devil is in the details. I wouldn't risk my own neck by attempting a citizens arrest in a place like SF, because I think the prosecutors/etc there would be more interested in making an example out of me for daring to care, than punishing the actual criminal. Evidently the police of SF feel similar.
1. https://en.m.wikipedia.org/wiki/Murder_of_Ahmaud_Arbery#Peop...