Army to support police patrols?

Quite rightly, the number of policemen employed by the state was reduced as crime fell after the millennium. Not only did reducing numbers directly cut the wages bill it also reduced the burden on the public purse of pension payments.
But now, as street crime. particularly violent offences, rise, there is a clamouring for more policemen at a time when budgets continue to be squeezed. What is the solution?
May I suggest that patrolling policemen, bobbies on the beat, might be replaced by others, already trained in patrolling and surveillance and, most importantly, available without additional costs. Could it not be possible that troops, not on active service, be used in this capacity. They need not physically carry arms but should be side armed, could wear specially designed uniforms and have the right to detain suspects using powers of citizen's arrest.
There are benefits for the troops, bored with little or no action when barracked. It keeps them sharp and enhances skills. Troops of different regiments can be rotated in different towns and cities so as reduce effects of accumulated antagonism.