Two “Stop the Violence” organizers allegedly beat one of their colleagues so severely that he vomited blood and was left unconscious in critical condition. Nikole Ardeno and Emanuel Velez, both 30, accused their former roommate of stealing their property, and allegedly punched and kicked him in the street until he had seizures. Arrested moments later, Ardeno was still wearing the same “Stop the Violence” T-shirt she had on the night before when she coordinated a march protesting two recent shootings, Washington Police Chief Chris Luppino said. The victim, Joshua Magraff, also is a community organizer with the anti-violence group, and...