WST DTM/Law Enforcement
From Halopedia, the Halo wiki
The DTM/Law Enforcement is a version of the DTM Series used by Law Enforcement agencies. It features a solid stock and no pistol grip. The shotgun would appear very similar to the 20th century Remington Model 870 shotgun,used in World War 2.
The lack of a pistol grip might be a downside in military combat, but allows the user to hold the shotgun with one hand comfortably. [1].
