After the second inmate slashing of the day, guards on Rikers Island were checking inmates for weapons — an exhaustive process that involves repeated strip searches and the use of screening devices.

Standing outside a search pen, the new assistant chief for security, Eliseo Perez Jr., locked eyes with an inmate.

“This guy thinks he’s tough,” Chief Perez said, according to prosecutors in the Bronx. And then he ordered his subordinates to kick the inmate’s teeth in, the authorities said.

On Wednesday, Chief Perez, who recently retired, and nine current officers and supervisors with the New York City Department of Correction were arraigned on criminal charges in connection with that episode on July 11, which resulted in the beating of the inmate and a coordinated effort to cover up the attack, according to an indictment.