This is a great photo. The fellow holding the clipboard appears to be a Justiz (Prison Police) NCO. From his collar tabs I suspect this is his armory. Justizverwaltung Police wore this style of tunic with concealed buttons on the front with distinctive insignia. They were responsible for prisoner control so such an armory in a prison environment is likely. Weapon-wise the MP were certainly used by them and what appear to be flare pistols are likely nearly identical tear gas guns.
Here are a couple of uniforms from the Prison Police.