More than 400,000 crime records could have been affected by a data blunder, with records for serious offences supposed to be kept forever accidentally deleted and police fearing criminals may not be caught, a letter from a senior officer reveals.
The records were accidentally deleted due to a coding error on 10 January, and the incident affects fingerprints, DNA, and arrest records on the police national computer (PNC).
The Guardian has learned that records related to serious offences, meant to be kept “indefinitely”, have been affected and police have already suffered what they term as “near misses” for serious crimes.
Police leaders are also concerned that the chaos may cause them to hold data they should have legally deleted.
Pressure is mounting on the home secretary, Priti Patel, to give a full account of the blunder affecting the PNC, which is run by the Home Office.
A letter sent to senior officers on the National Police Chiefs’ Council (NPCC) on Friday from deputy chief constable Naveed Malik, lead for the organisation on the PNC, outlines the scale of records affected: “In PNC approximately 213,000 offence records, 175,000 arrest records and 15,000 person records have potentially been deleted in error. In terms of understanding the potential linkage between records, a one-person record can have multiple arrest records and one arrest record can have multiple offences linked to it.”
The DNA database is connected to the PNC and has also been hit, the police chief’s letter reveals. It says: “Approximately 26,000 DNA records corresponding to 21,710 subjects have potentially been deleted in error, including records that have previously been marked for indefinite retention following conviction of serious offences.”
Technicians are also scrambling to recover tens of thousands of fingerprint records, according to the deputy chief constable’s letter, which says that “30,000 fingerprint records and 600 subject records have potentially been deleted in error”.
Police fear offenders may be missed. Malik wrote in the letter to police chiefs: “As the National DNA Database and the National Fingerprint Collection currently contain incomplete sets of biometric records, there is the possibility that biometric matches between crime scenes and offenders may not be identified.”
The letter reveals cases where some people police suspect nearly got away because of the blunder: “We are aware of a couple of instances of ‘near misses’ for serious crimes where a biometric match to an offender was not generated as expected but the offender was identified through matches between scenes. However, in these circumstances, without a direct match report to the subject, it may be more challenging for police to progress to an interview or arrest.
“We are also aware of at least one instance where the DNA profile from a suspect in custody did not generate a match to a crime scene as expected, potentially impeding the investigation of the individual’s involvement in the crime.”
The Home Office said it was working with police to assess the impact of the error, which reportedly occurred by accident during a weekly “weeding” session to expunge data.
The policing minister, Kit Malthouse, said the PNC was a large database of information that requires maintenance, adding: “Unfortunately down to human error, some defective code was introduced as part of that routine maintenance earlier this week and that’s resulted in a deletion of some records and that’s currently under investigation.
“We are now working very quickly with policing partners and within the Home Office to try and recover the data and assess the full extent of the problem.”
Although officials are “not entirely sure as yet” whether the problem has had an operational impact on the police, Malthouse said, contingency plans have been put in place to ensure investigations can continue.
The shadow home secretary, Nick Thomas-Symonds, called on Patel to make an urgent statement: “It’s not good enough for the home secretary to hide behind her junior minister on this when there has been such a major security breach on her watch.
“It’s now vital that she makes an urgent statement outlining the true scale of the issue, when ministers were informed and what the plan is to provide public reassurance. Yet again, Conservative incompetence is putting people’s safety at risk.”
He added: “This is an extraordinarily serious security breach that presents huge dangers for public safety. The incompetence of this shambolic government cannot be allowed to put people at risk, let criminals go free and deny victims justice.”
On Friday night Thomas-Symonds wrote to Patel, urging her to show “personal responsibility and leadership” and asking when ministers were first made aware of the breach, if local forces had been informed of potential impacts in their area, and what steps were being taken to retrieve the data.
The PNC allows real-time checks on people and vehicles. Millions of records are kept on it, and they are removed automatically after certain periods depending on the nature of the offence, the suspect’s history and other factors.
The deletion also caused chaos with the visa process. Applications, which are checked against the PNC, were suspended for two days but have now resumed.
A spokesperson for the NPCC said: “We are aware of an issue with the PNC and are working closely with the government to understand the potential operational impacts.”