IPCC chief: ANPR is 'a victim of its own success'

The commissioner of the Independent Police Complaints Commission (IPCC) has said there are severe difficulties in running automatic numberplate recognition systems.

Nicholas Long said that ANPR systems are often overwhelmed with information and cannot be monitored properly.

He was speaking following an investigation by the IPCC into police use of ANPR intelligence on Peter Chapman, who murdered 17-year-old Ashleigh Hall in October 2009.

"The ANPR system is championed as a wonderful tool for police forces," Long said. "However, it has undoubtedly become a victim of its own success in that the amount of information contained in the system and the hits generated have made it virtually impossible to monitor adequately, given police resources."

The investigation concluded that the quality of the information put into the Police National Computer (PNC) varies greatly and the PNC is sometimes being used for minor issues. As a consequence, a possible overload of information on ANPR monitoring systems could lead to high- and medium-priority issues being missed.

In relation to the Chapman case, the IPCC said that on 23 October 2009 Merseyside Police put information on the PNC stating that Chapman was wanted for arson, breach of the sex offenders' register and theft, along with information about the car he was driving.

Between 23 to 26 October 2009, static ANPR cameras in Cleveland, Durham and North Yorkshire picked up Chapman's car on 16 occasions. But it was only information from the last occasion at 5.07pm on 26 October which resulted in his arrest.

Chapman pleaded guilty to murder at Teesside Crown Court in March 2010 and was sentenced to life imprisonment.

The investigation determined that the systems for monitoring ANPR hits differed greatly between the three police forces.

In the North Yorkshire police area there were 14,413 ANPR hits on the four days in question. Two hits related to Chapman's car, but the force knew nothing of them at the time because it only monitored its ANPR systems in relation to specific operations.

The Cleveland police area has some 2,650 hits per day. There were 12 hits on seven different cameras relating to Chapman's car, but again the force does not monitor its ANPR systems around the clock.

In the Durham constabulary area there are approximately 6,000 hits per day and two hits were generated in relation to Chapman's car on 25 October. The constabulary's control room staff monitor its ANPR system and area dispatchers have responsibility for the monitoring of ANPR activations within their geographical area.

A hit showing Chapman's car at 7.48pm went unnoticed because relevant staff were not logged into the system. A hit at 8.25pm showed Chapman's car leaving the Durham constabulary area, but the ANPR system was configured so that vehicles leaving the area were not flagged on dispatchers' systems.

Long called for a full review of how the ANPR system is operated including the development of consistent policies for the monitoring of the system across all forces, the prioritisation of information and the accurate input of data.

This article was originally published at Guardian Government Computing.

Guardian Government Computing is a business division of Guardian News and Media, covering the latest news and analysis of public sector technology. To register, email james.longhurst@guardian.co.uk at Guardian Government Computing.