riot gear 
noun [mass noun]
Protective clothing and equipment worn by police or prison officers in situations of crowd violence: officers in riot gear...
- Behind me the door crashed open and a police officer in full riot gear came through waving a shotgun, I'd already recognised her from her voice, I put my hands behind my head and stood there.
- More than 1,000 students clashed with police in riot gear, blocking the President's access to the site and forcing him to pull around to a back gate.
- Just as I was deciding to get out and walk, the protestors upped and left for another intersection, pursued - we saw minutes later - by dozens of police in riot gear.