Their thinking goes something like this:

There are only two kinds of people: Bad People and Good People.

Good people can’t do bad things, only good things (so if they do a ‘bad thing’ it was obviously just an innocent mistake because they’re Good People).

Bad People can never do good things, only bad things (so if they do a ‘good thing’ it was obviously just to further some sinister agenda).

It’s nearly impossible for a Bad Person to become a Good Person, because Bad is something you are, not something you do. It’s basically genetic that they’ll always feel the urge to do Bad. Only a Higher Power like God has the power to ‘save’ a Bad Person, they can never become Good on their own.

I am a Good Person.

Since I am a Good Person, I can only do good. And I only interact with Good People, and support Good People in politics/whatever because interacting with and supporting Bad People is bad, and I don’t do bad things.

Those people I hang out with said that group over there is Bad. Since they’re Good People (because I interact with them) what they say must be true.

The problem with Epstein is he short-circuits this exceptionalism-tribalism sort of thinking, for two reasons.

First, because he hung out with what they consider ‘Good People’ (which they define as rich white males generally, and people they’ve supported in the past—remember, they only support Good People, because they’re not Bad). But Epstein was so vile, his acts so vile, and the ‘Good People’ so happy to participate, that their brains can’t square the circle of Good Person knowingly and enthusiastically and repeatedly doing Bad Things.

And second, because the vile things he did have been harped on by all the ‘Good People’ they know as being Evil and Vile since way, way before any of this Epstein stuff was even hinted at, so they have a harder time just sweeping it under the mental rug with a ‘they didn’t know!’ or ‘they didn’t mean it!’

Not sure what your job or relation to the person is (besides just coworker), but if you have one, I'd talk to HR about hate speech and possibly harassment. Certainly not worth a police report, but maybe if their boss comes at them with a "chill tf out with that shit" then maybe they'll shut up at least. The 'Hitler was right to kill Jews' part especially.

Edit: Or just post photos of the messages to Facebook and let the crowd roast him over an open fire.