Live facial recognition is a surveillance technology that scans faces
captured by a live camera feed in real time, and automatically compares
each one against a pre-loaded list of people the police are looking for —
the "watchlist." When the system judges a face to be a likely match, it
generates an alert; an officer then reviews the alert and decides whether
to stop the person.
This page is a plain-language, factual overview. It doesn't
offer legal advice, and it doesn't try to settle the policy debate around
this technology — it exists so readers can understand what the data on
this site is actually describing.
How a deployment works
Watchlist creation. A police force compiles a list
of individuals it's looking for — this might include people wanted on
warrants, individuals subject to court orders, or people reported
missing. Watchlist size and composition vary by deployment and force,
and are not always published in detail.
Camera deployment. Cameras are set up in a public
location — typically mounted on a police vehicle or a temporary rig —
for a fixed window of time, usually with signage nearby.
Live matching. As people pass the cameras, the
system extracts a biometric template from each face and compares it
against the watchlist in real time.
Alert and review. A likely match triggers an alert
to an officer, who reviews the underlying images before deciding
whether to approach the person. The system does not act
automatically — a human makes the final call.
Key terms used on this site
Deployment — one use of LFR at a specific place and
time; the basic unit each row of data on this site represents.
Watchlist size — the number of people on the
watchlist for that deployment, where a force discloses it.
Faces scanned — the number of faces the system
processed and compared against the watchlist during a deployment. Not
every force records or discloses this per deployment — see the
Methodology page for how gaps
and estimates in this figure are handled.
Alert — a system-generated potential match, flagged
for human review.
True / false alert — whether an alert is later
judged, by an officer, to be a correct match or not. Definitions and
review processes vary by force.
Context worth knowing
LFR use by UK police has expanded significantly since its early trials,
and remains a live policy debate. Points raised on different sides
include:
Police forces and the Home Office have generally framed LFR as a
tool for locating wanted individuals and preventing crime more
efficiently than manual identification.
Civil liberties groups and some independent researchers have raised
concerns about mass biometric surveillance of the public, accuracy
differences across demographic groups, and the adequacy of the legal
framework governing its use.
The technology's legal basis has been tested in UK courts — most
notably in Bridges v South Wales Police (2020), in which the
Court of Appeal found the force's use of LFR unlawful on specific
grounds relating to discretion and equalities assessment, without
ruling out LFR use in principle. Forces have since adjusted policies
in response.
What this site does and doesn't do: LFR Monitor
republishes aggregate deployment statistics that police forces have
already made public. It does not identify individuals, does not contain
images or biometric data, and does not take a position on whether any
specific deployment was lawful or justified — it exists to make already-
public data easier to see in one place.
For how the underlying figures are collected and
harmonised across forces, see Methodology.