Police in Albuquerque on Tuesday announced they had arrested a former city council candidate who they say shot and wounded a man at a protest that grew contentious as demonstrators clashed with a militia group.

The Monday night episode — which erupted after a crowd tried to tear down a monument to Spanish conquistador Juan de Oñate — appeared to reflect a phenomenon that federal and state officials have long warned about: Protests over racial injustice, such as the ones currently roiling American cities, can draw a medley of fringe actors or groups with their own ideological agendas.

Recent protests against Oñate statues in New Mexico mirror similar calls to tear down Confederate monuments amid a rise in demonstrations after the killing of George Floyd, who died on May 25 after a Minneapolis police officer knelt on his neck for nearly nine minutes.

In the hours leading up to the violence Monday, protesters faced off with members of an armed group that calls itself the New Mexico Civil Guard and counterprotesters toting “All lives matter” […]