While I don't agree with the hidden premise of:

It is far too easy to overlook the impact that violence in defense of white supremacy has on the Black and Brown communities.

that Kyle Rittenhouse was defending white supremacy, I'm curious if some of what the ACLU is writing is true. Particularly,

Months of research and open records requests have uncovered many incidents in which police encouraged white militia members to become armed vigilantes in the street due to their failure to control the crowd.

...our investigation exposed how Kenosha law enforcement used violence against protesters and drove them toward white militia groups, in ways that escalated tensions and almost certainly led to these shootings.

The part about driving the protestors into people trying to protect the community sounds right (although I would not describe them as vigilantes or white militia groups), I would very much like to see evidence they uncovered during their investigation that the police encouraged this so-called armed vigilantism due to their failed crowd control.