Concerns have been raised about the practice after a report from the police watchdog revealed custody photographs are retained on a force database even when no further action is taken against the individual concerned.
The report by HM Inspectorate of Constabulary in Scotland (HMICS) called for an independent commissioner to be appointed to oversee police use of biometric data such as fingerprints, DNA and photographs.
It warned that there is currently no statutory framework or legislation in Scotland regulating how the police use or retain photographic images.
While fingerprint and DNA samples are destroyed if criminal proceedings are dropped, mugshots are kept on the police’s “custody software” under a practice which predates the formation of Police Scotland, the national force led by new chief constable Phil Gormley.
Most images are kept for at least six years, but those accused of more serious offences have their mugshot retained for up to 12 years.
However unlike in England and Wales, the images are not uploaded to the Police National Database (PND), a tool which allows officers to search for a match among custody pictures using images taken from sources such as CCTV and mobile phones.
HMICS said Police Scotland was retaining mugshots on file to assist in investigations where those arrested have given false identity details or to help when retrospective complaints are made by those taken into custody.
But Graeme Pearson, Labour’s justice spokesman and a former senior police officer, said the practice had to stop.
“I don’t think it’s right,” he said. “If a decision is taken that there’s to be no prosecution or if the person is found not guilty, then the images, DNA and other biometrics should all be destroyed at that point. There’s no justification for holding on to them.”
Liberal Democrat justice spokeswoman Alison McInnes said: “This report raises questions about why some records have to be destroyed as soon as possible after someone is cleared of wrongdoing but photos can be kept for up to 12 years. I will be writing to Police Scotland to seek a more detailed explanation.”
Since 2014, UK police forces have been able to carry out “facial searches” using mugshots stored on the PND, which was introduced after intelligence gaps were identified following the murder of schoolgirls Holly Wells and Jessica Chapman by Ian Huntley in 2002.
A Police Scotland spokeswoman said: “Custody images – including those of a person who has not been charged – are retained to assist in the investigation of circumstance where arrested persons may have provided false identity details to the police, or in other circumstances, such as retrospective complaints being made about a particular custody episode.”