Peter James - Death Comes Knocking - Policing Roy Grace's Brighton

PSU— Police Support Unit. A unit of police officers trained and equipped to deal with public order or crowded events. Usually comprises one inspector, three sergeants, eighteen constables together with two medics and three drivers.

RPU— Roads Policing Unit. The new name for the Traffic Division.

RTC— Road Traffic Collision (commonly known as an ‘accident’ by the public, but this term is not used as it implies no one is at fault when usually someone is).

SIO— Senior Investigating Officer. Usually a Detective Chief Inspector who is in overall charge of the investigation of a major crime such as murder, kidnap or rape.

SOCO— see CSI.

SSU— Specialist Search Unit. The team who provide expert search skills such as searching underwater or in confined places at height, as well as locations where a high degree of search expertise is required, such as large or complex crime scenes.

TFU— Tactical Firearms Unit. The small, permanently armed department of the police that responds to firearms incidents. They often deploy in ARVs (see above), and also have other specialist capabilities.

TPAC— Tactical Pursuit And Containment. Describes a range of methods for managing and terminating police pursuits, including boxing the target vehicle in using police cars and, where necessary, causing it to stop by use of controlled collision.

ABC— Assume Nothing, Believe No-one, Check Everything. The Senior Investigating Officer’s mantra for maintaining an open and enquiring mindset in investigations.

Copper’s Nose— a police officer’s instinct. The sixth sense which often guides an officer’s suspicions.

Golden Hour— the first hour after a crime has been committed or reported when the best chances of seizing evidence and/or identifying witnesses exist.

PC Rain— so called as a good downpour has a greater chance of clearing people, including drunks and criminals, off the street than any number of police officers can!

Q Word— short for ‘quiet’. Emergency services personnel never say the word ‘quiet’, as it invariably is a bad omen, causing chaos to reign!

Shit Magnet— Slang for a police officer who seems to attract trouble and around whom disaster invariably reigns.

Police ranks are consistent across all disciplines and the addition of prefixes such as ‘detective’ (e.g. detective constable) does not affect seniority relative to others of the same rank (e.g. police constable).

These can vary between forces.