assuming the newspaper's allegations are correct, in the best plausible case, her family sues the city government for wrongful death, qualified immunity shields the thugs, the family wins the case and gets awarded a large amount of money that the government has to pay, which raises taxes on the people living in the area in order to pay it
there is essentially no chance that the district attorney's office will prosecute crooked cops; those crooked cops are their closest collaborators when they are doing what they do 99% of the time, which is prosecuting poor people who don't work for the government. the prosecution of derek chauvin was no more a matter of business as usual than the prosecution of julian assange
(First two entries on this page) https://www.justice.gov/crt/statutes-enforced-criminal-secti...