The poor houses and prisons were a common source of soldiers for the British Empire, the deal in the latter case being a pardon conditional on their enlistment. Which is at least part of the reason why American colonists were not too happy at the prospect of quartering them in their households:

 

Manpower was the key ingredient in Germaine's battleplan. From the start of the war there were difficulties in procuring sufficient troops for operations of the scale he had in mind. During 1775-1776 garrisons in Ireland, Gibraltar, and Minorca had been pared to the bone and, as the war progressed, an intense recruiting campaign was undertaken in Britain.

It was never an easy job to tempt men to enter a world where they could expect a flogging for a trifling misdemeanour, low pay, thin rations, capricious officers, exposure to danger and the contempt of so-called respectable society. Patriotism, that is soldiering, was regarded by Samuel Johnson as the last resort of the scoundrel; in other words, a man without the ability or inclination to live honestly. It was a harsh judgment, but supported by current practice; many desperate recruiting officers scoured prisons to fill out the ranks. In 1776, Lieutenant Ridout of the 46th Regiment discovered some 'very fine lads' in a Shrewsbury gaol for 'petty offences' and obtained their pardon and enlistment into his regiment.

...Captain Peebles of the Black Watch found some linen and six or seven bottles of rum and wine taken from his tent, and observed that 'there are some sad rascals in this Battalion who are wicked enough to do anything, and have the cunning enough to escape.^1

 

1. Lawrence James, The Rise and Fall of the British Empire, (New York: St Martin's Griffin, 1994), 111-112.