Pic--Andy Berry of the Police Federation said delays meant "losing the opportunity to prevent further crimes and further victims"/wp/bbc
Special report(wp/bbc):::
Hundreds of fingerprints are waiting to be analysed by experts because of "deeply concerning" forensic delays.
Figures show more than 830 fingerprint cases were waiting to be analysed by South West Forensic Services in May.
Examination of some digital material was being delayed by up to 12 months, according to the Police Federation.
South West Forensics said it was urgently recruiting staff to "cope with demand" and it was "committed to safeguarding victims of crime".
In Cornwall, a multiple-burglary victim has been paying £400 per week for an overnight security guard to protect his shop because he has no confidence in the police catching the culprit.
Three months since the latest burglary, Thana Singam, from Hatt Service Station, said he was still waiting to hear whether the police had found a fingerprint match.
"They told me forensic results would take six weeks," he said.
Mr Singam said the cost of stock taken and repairs of damage caused had totalled more than £20,000 across the three burglaries.A former employee of South West Forensic Services - which launched in 2014 and covers the Devon and Cornwall, Dorset, Avon and Somerset and Wiltshire police force areas - told the BBC the "whole point of regional forensics was to save money, but quality has not been maintained".
"The service is letting down the public and highly trained, skilled staff. Everyone is unhappy and investment is desperately needed," they said.Figures obtained through a BBC Freedom of Information request showed delays in digital forensic cases, which include tablets and mobile phones, increased in a two-month period.
For Devon and Cornwall, 160 cases - including almost 700 devices - were waiting to be examined in May - compared to 119 cases in March.In May, forensic bosses said there were delays of at least three months but Andy Berry, from the Police Federation, said investigators had told him about a six to 12-month wait for digital material.
In one case, he said an officer reported a 10-month wait to examine a phone belonging to a suspected child sex offender.
Mr Berry said all delays were "deeply concerning and it was letting the public down".
Martyn Bradford, director of South West Forensic Services, said a formal review and changes of working practices would help address backlogs.
"Due to the growing amounts of data and the complexity of devices, the speed of processing [digital] exhibits is becoming more challenging," he added.