Riot Police Infected. The blood of its victims is cast all over its protective suit of armor. Because of its riot armor, its a lot harder to kill, and while its not aware of the weapon and shield attached to its suit, when it flails its arms they are just as deadly.
The riot zombie walks slowly, but because of its highly armored state, when allowed to close in it can inflict serious damage very quickly by flailing its arms (and thus its shield and beat stick). It can also rip chemical boils off of its arms and chest and throw them, where they explode upon impact like grenades. These infected boils have a strange glow to them, this makes the Riot Infected a bit easier to see in the dark, since the rest of its body is covered in a dark suit.