The Specialist Firearms Command is the firearms unit of the Metropolitan Police. The Command is responsible for providing a firearms-response capability, assisting the rest of the service which is not routinely armed.

The Territorial Support Group (TSG) is a Met Operations unit of London's Metropolitan Police Service (MPS) which specialises in public order policing, amongst other specialist areas. In 2012 it consisted of 793 officers and 29 support staff. The TSG is a uniformed unit of the MPS that replaced the similarly constituted Special Patrol Group in 1987. TSG units patrol the streets of London in marked police vans or "carriers"; using the call sign prefix "Uniform". Generally each carrier has an advanced (police) driver, seven constables, and a sergeant. Territorial Support Groups often comprise three carriers, twenty one constables, and three sergeants reporting to an Inspector. They separately patrol designated areas experiencing serious levels of gang violence or disorder. When deployed, it is by the MPS Information Room. Due to the public order nature of their role, numerous carriers will often be assigned. TSG officers can be identified as TSG from the distinctive "U" in their shoulder numbers. Some TSG officers are also plainclothes officers, carrying a taser and handcuffs.