Sheriff's Emergency Response Team. This patch is currently worn by members of the SERT Team (Tactical/SWAT) and the Hostage Negotiation Team. The patch is the same style and wording as the regular patch, however the background twill is OD green with black embroidery. This patch is worn on OD green BDU's (Battle Dress Uniforms) in tactical situations. This patch is currently in use and was introduced in the early 1990's. Prior to this, the SERT team used regular patches dyed black. For the 1984 Olympics, the team utilized black jumpsuits, with the Department patch silk screened in white on the shoulders.