A group of Rikers guards, accused of beating an inmate at the behest of their superior and then covering it up, did so because he stared at supervising warden Eliseo Perez Jr., prosecutors said on Wednesday. “This guy thinks he’s tough,” Perez allegedly told his team. “I want you to knock his f—ing teeth in,” he ordered. The inmate, Jamal Lightfoot, wound up with broken eye sockets and nose. The ten defendants say they were using appropriate force, restraining a violentinmate.