 In 1980 the Tactical Response Group (TRG) was created, becoming operational in May 1982, with units divided into groups of 25 officers across the four metropolitan regions with a primary role of responding to riots, demonstrations, disasters, saturation patrols and to support SWOS at emergency hostage/siege situations.TRG officers were mainly drawn from the ranks of general duties police whereas SWOS were drawn from Detectives sections and branches.In June 1991 both units were rationalised and dissolved with the creation of the Tactical Operations Unit with the aim of resolving high-risk incidents by containment and negotiation, with minimal or judicious use of force to be applied only as a last resort and based on full and careful assessment.