Rookie officers with less than five years experience now make up almost half of some police forces.
The proportion of inexperienced officers making up total numbers across the country has doubled since 2016. Meanwhile the number with more than 20 years under their belt has fallen.
Kevin Moore, a retired chief superintendent and former head of CID at Sussex Police, said: “The lack of experience is having a detrimental impact on the quality of policing.
“Policing is now paying the penalty for Government cuts post-2010, which saw overall numbers drop by over 20,000.”
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He said recruitment efforts by the current Government may restore the numbers to 2010 levels, “but inevitably they will be less experienced”.
Former officers say the high proportion of novices means incidents that now cause difficulty would previously have been dealt with swiftly thanks to the confidence and experienced of a veteran officer.
In 2016, rookies were outnumbered by experienced officers, with four for every six. Now there are nine rookies for every six who have 20 years or more experience.
In England and Wales, 47,370 of the 142,505 officers have fewer than five years’ experience. That is 33% of the total.
Six years ago newer recruits numbered just 19,242 – 15% of the total 129,773 force.
Over the same period, the number of officers with 20 years or more service has fallen from 31,511 to 29,447.
In both Northamptonshire and Bedfordshire, 43% of the force have been in the job for less than five years, with just 13% and 15% respectively serving more than 20 years.
In Essex the figure is 41% to 16%. And in both Hampshire and Leicestershire, 23% have fewer than two years in the job.
David Spencer, of the Centre for Crime Prevention, said: “While all will have been thoroughly trained, you can’t put a price on experience. The growing number of novice officers is a real concern. Young officers learn on the beat – they need experienced officers alongside.”
The Home Office has said retaining experienced officers is as important as hiring new ones, adding: “Our investment enables forces to grow their supervisory ranks and staff to support new officers.
“We expect forces to use this to ensure all new officers are effectively supported to deliver best outcomes for the public."