Facial Recognition Technology

What Is Facial Recognition Technology?

Cheshire Constabulary uses facial recognition technology in a legal and ethical way to prevent and reduce crime while also improving investigations. 

Facial Recognition is a technology capable of comparing a human face from a digital image against a database of faces – in Cheshire Constabulary’s case this is national custody photographs.

Custody images are legally held and stored under the Police and Criminal Evidence Act 1984.

How does Facial Recognition Technology work?

It analyses key facial features and generates a biometric template of these features. It then compares them against the biometric template of known faces in a database, generating possible matches.

• Live Facial Recognition (LFR) is the use of facial recognition where all persons passing a camera(s) are analysed by the system with results being generated in tandem with events. The use of overt live facial recognition is to locate people on a watch list who are sought by police.

Cheshire Constabulary uses Technology Retrospective Facial Recognition (RFR)

What is Retrospective Facial Recognition (RFR)?

Cheshire Constabulary currently utilises Police National Database (PND) facial recognition technology.

RFR technology is used to identify a suspect efficiently and effectively. When a suspect of a crime remains unknown, RFR will be used.

RFR is utilised post event as part of a criminal investigation. Investigators capture images typically from from CCTV, mobile phone footage or social media. These images are then compared against national custody images.

After a search is made, the technology suggests possible matches from the reference image database from the most likely to the least likely possible match.

An operator will review the matches to determine whether a match has been made. If the operator decides a match has been made, they will inform the investigating officer. The investigating officer will review the suggested match and add the person to the investigation as a suspect.

Examples on when Cheshire Constabulary may use facial recognition:

• A person has been captured on CCTV stealing items from multiple shops across Cheshire. The CCTV image can be put through the database and see if a match for an individual who was known to police.
• A burglary has taken place in Chester, a doorbell camera has captured the face of one of the people who have targeted the address. The image can be put through the software and a match could be received on an individual known to police.
• Officers have come across a person who they suspect has committed an offence and has refused to provide their details. Officers can take an image and put it through the system to obtain a match.

You have my image - can I request that you delete it so it can't be used by this technology?

We understand people may have concerns, but we are compliant with the Data Protection Act 2018 and the software will be used in a legal and ethical way.

Under certain circumstances, you have the right to request your data or the right to ask the Constabulary to delete your personal data to prevent its continued processing where there is no justification for us to retain it.