In 1968, outside the Democratic National Convention (DNC) in Chicago, police violently cleared the streets of antiwar protesters, smashing heads and clubbing with abandon. Inside, even some Democratic Party officials blanched at the level of brutality. Abraham Ribicoff, a senator from Connecticut, denounced the police’s “Gestapo tactics” from the podium of the convention hall, earning the ire of Chicago mayor Richard J. Daley and the applause of many delegates.

In the decades since, domestic law enforcement has stepped up its efforts to quell political dissent. While no convention since has devolved into such chaotic brutality, policing today is arguably more planned, militarized, and indiscriminately violent.

The contemporary policing model — one of “strategic incapacitation,” as the sociologist Patrick Gillham terms it — developed as a reaction to the global justice movement of the late 1990s and early 2000s.