Line of Duty: A handy guide to police terms and…

Line of Duty: A handy guide to police terms and acronyms like 'CHIS' and 'UCO'

Line of Duty is back on our screens and audiences from across the UK are already tuning in and getting to grips with the latest AC-12 investigation.

Almost 9.6 million people watched the first episode of season six on Sunday night, a marker of just how popular Line of Duty has become.

But even with its growing popularity, Line of Duty has never compromised by playing down the police lingo or the police procedural terms used by the characters.

This means that things can sometimes be lost, with audiences not understanding certain terms or acronyms that officers use when talking to each other.

This was the case in the first episode of the new season, when a 'CHIS' (Covert Human Intelligence Source, i.e a police informant) gave a tip off about a high profile killing, which kickstarted the series' action.

While everyone at the Hillside Lane Station naturally knew the meaning of the term, audiences were left perplexed and turned to Google to help them out.

To get audiences ready for further terms which might come up in the coming episodes, here's a guide to acronyms and terms used in Line of Duty:

AC-12 - Anti-Corruption Unit 12

AFO - Authorised Firearms Officer

ARU - Armed Response Unit

ARV - Armed Response Vehicle

CHIS - Covert Human Intelligence Source

CID - Criminal Investigation Department

COM - Covert Operations Manager

CPS - Crown Prosecution Service

DCI - Detective Chief Inspector

DCS - Detective Chief Superintendent

DI - Detective Inspector