The use of Automatic Number Plate Recognition (ANPR) systems in policing has proved highly successful in tracking criminals, preventing and detecting crime, targeting uninsured and licensed road users and bringing people to justice.
They assist police in investigating crimes, including theft, burglary, drug offences, violence, sexual assaults and murder.
But people are often interested to know exactly what ANPR is, what happens to the data collected by police and who has access to it.
Put simply, ANPR uses cameras, which can be mobile, portable or placed at fixed locations, to capture details of vehicle registration marks or from number plates, along with the time and location of the vehicle. This information can then be instantly checked against a range of databases of vehicles which are of interest to police. These include the Police National Computer, and those supplied by the Driver and Vehicle Licensing Agency and the Motor Insurers’ Bureau.
There are usually two images stored, on a computer in the force where the vehicle was sighted. One of a number plate itself, and then a second which is a wider overview of the vehicle. Each police force then shares its data with a national computer system which can be used to identify patterns of behaviour by known criminals as they cross county boundaries or travel across the country.
All of the information is stored on computers locally and nationally for a maximum of two years.
If a vehicle matches one stored in any of these databases, an alert can be triggered, which police refer to as a ‘hit’. This hit ensures officers are immediately alerted to vehicles that are stolen, unregistered, unlicensed, uninsured or are believed or known to be involved in crime.
A hit can instantly tell an officer if a vehicle associated with a known criminal was in the area at the time of a particular crime.
The system can also be used in real time so police can intercept and stop a vehicle and make arrests if necessary. This technique has been used to successfully detect and prosecute many cases of major crime.
When a hit happens, each one is marked high, medium or low priority, and each category has a particular police response to assist with prioritisation. High priority relates to events where life is at risk and can include child abduction, murder and terrorism.
Medium is used for major or serious investigations and low priority is used for crimes that are a priority within a locality, where the vehicle or occupants need to be traced.
There are many benefits to using ANPR but the police recognise it has to be used in a proportionate and responsible manner with effective safeguards in place to ensure against inaccuracy and misuse. My aim is to inform the public and reassure them that ANPR is governed by a set of standards and principles with safeguards in place to deal with the information gathered, which are outlined in the Human Rights Act, Data Protection Act and are subject to guidance from the Information Commissioner.
The ANPR community was actively involved through consultation in the creation of the new surveillance camera code of practice and fully recognises the importance of such guidance.
We want to make sure there are no consequences for law abiding members of the public and a report, called Police use of ANPR, outlines a number of recommendations and a set of ‘Golden Principles’ which were devised with support from organisations outside the police service.
Among the golden principles is our belief that ANPR data should be used responsibly for the public good, to the benefit of both prosecution and defence cases. Access to such information should be restricted with clearly defined rules on who can gain access to it.
This area is always under review by the police and we want to reassure law abiding members of the public they have nothing to fear from ANPR. It is a powerful crime fighting tool which will continue to protect the public, while targeting criminals and bringing them to justice.
Julian Blazeby is Assistant Chief Constable of
, and ACPO lead for ANPR.