Counter Terrorist Specialist Firearms Officer

The Counter Terrorist Specialist Firearms Officer (CTSFO) is a department within the Metropolitan Police of the UK. It doesn't only have jurisdiction in London but across the whole country. 
Duty.
The CTSFO firearms officer have reasonability's in conducting warrant operations in London or other parts in UK for high-risk situations or counter terrorism operations across the Kingdom. They also escort high risk diplomats when entering the nation. 
History.
CTSFO is the highest standard of authorized firearms officer within the National Police Firearms Training Curriculum (NPFTC). Both of them were established by the Metropolitan Police Service in 2012.