I don't know anything about Hammond's case, but it seems a poor way to deal with Neo Nazis. Physically beating them up will never decrease their numbers. That's the same mistake we make with our foreign policy.
Worked in the late 70s. I think antifa groups have been too quick with the violence since then -- the ANL was responding to violence, it didn't just decide to start beating up neo-Nazis because neo-Nazis, but violence was both successful and justified at least once.