So where are the studies regarding left wing violence?
Left wing violence is largely institutionalized. It exists in anti private sector activities including but not limited to the taking of land, wealth, freedom and life, whether from those deemed a threat to institutions or simply from those from whom the confiscation of their properety will benefit the state.
To study left wing violence it is necessary to research government abuse of authority. That is a herculean task.
This research, manifestly politically motivated, is leading us into a war of suppression by the government of citizens who oppose tyranny.