There should be some distinction between a reward paid to employees, which is more like a commission; and one that is paid to customers or the general public, which is more like vigilantism.
one further distinction exists in that there are people poor and desperate enough to commit crimes in the hopes of bieng jailed and there by housed and fed, though as they are such meager crimes,are then released, so the 1£ reward they might try and claim would be a significant incentive.
it might be easy to dismiss my conjecture, but it is the sort of thing people in compromised situations think up, as they struggle to survive in a world where the logic is very different and in many ways diametricaly opposite.....nothing to loose + something to gain= <