In my experience, asking supporters of immediate prison abolition what will be done with killer cops, fascists etc. yields 1 of 3 answers:

1. "Google it"
2. Prison under another name (eg "community supervized isolation")
3. An objectively worse punishment like exile or execution

And yes, I've googled it, and no, there's no better answer.

The Marxist approach here is the same as wrt the state: we want a world without prisons, but as long as classes exist, class conflict will exist, and with it the need to contain those who seek to keep us down. Any attempt to skip past this leads to inextricable contradictions.

The replies to this very reasonable question is another example of things I've talked about in this thread. Supporters of immediate prison abolition simply have no answers other that aren't some form of dodging the question. https://twitter.com/ldrinkh20/status/1277687896871493632