The building was designed to hold about one hundred and fifty prisoners, but the actual population usually exceeded this figure by at least another hundred, all crammed together whether awaiting trial or already convicted. Inside it was chaos, with one guard to every ninety prisoners. Wives were permitted to visit overnight, prostitutes could ply their trade, gambling and dancing were permitted, children and farm animals ranged freely and newspapers were even delivered daily. The air inside was thick and filthy, and a virulent form of typhus, known as "gaol fever", carried away about thirty inmates a year. Prisoners pissed on passing pedestrians from grated windows and doctors generally refused to visit. Debtors, thieves and killers mixed socially and in this earthly Pandemonium hard currency, known as "rhino", meant everything. The rhino may not have exactly established a prisoner's innocence, but it could make life inside a deal easier, buying food, drink, tobacco, sex and more comfortable accommodation from the Keeper, rent on a good cell ranging from twenty to five hundred pounds per annum. This was the Newgate of Jack Sheppard and Jonathan Wild, described by a contemporary observer as: "a bottomless pit of violence, a Tower of Babel where all are speakers and no hearers".
(from The Literary Encyclopedia)
Throughout most of the eighteenth century in London, the punishment for theft of a shilling's worth of property and that for killing a man were one and the same: death by hanging. At the same time, London was in the midst of a crime wave that has been considered the worst in recorded history; footpads and cutpurses filled the city, and highwaymen plied their trade along every road leading to or from London. At the same time, the criminal (specifically, the highwayman) was held in high regard, as a figure of drama, masculine empowerment, and freedom from the financial and social strictures of the city. And it was into this environment, in 1728, that John Gay unveiled The Beggar's Opera.
Most crimes in eighteenth century London and its environs were theft of one sort or another. Robbery on the roads incoming and outgoing from London was rampant; in fact, most travellers leaving London could expect to be robbed at least once on the way. The city itself was hardly any safer; besides the footpads (muggers) and pickpockets which flourished in the crowded environment of the city, several methods of burglary developed specific to London of the time. One common practice, referred to in The Beggar's Opera in Act 1 Scene 10, was to rob a house, then set it afire, so as to prevent evidence of theft from being uncovered. Some enterprising crooks even arranged to have pickpockets work the crowd of concerned citizens as they fought the flames. Of course, violent crime, including murder, often accompanied these thefts. Highwaymen were often the most brutal of the lot; as they faced hanging whether they killed their victims or not, many decided that an extra charge or two of murder was a small price to pay for one or two fewer witnesses.
As dangerous as the thieves and highwaymen made the life of the average citizen of London, the methods of criminal justice made the eighteenth century a dangerous time to be a criminal. As previously mentioned, the punishment for most crimes was death by hanging; additionally, the road to the scaffold often held terrors all its own. First among these, and the most emblematic of the systematic corruption of eighteenth century London, was Newgate Prison.
The time of Newgate Prison's construction is unknown; however, there are records of it being used to hold prisoners as early as 1218. Destroyed by fire at least twice during its period of operation, it was rebuilt each time, and did not close permanently until 1902, to make way for the Old Bailey. During this time, Newgate was used to hold the accused on their way to trial, the convicted until hanged. The prison was also a debtor's prison, used to hold debtors until they could be ransomed by friends or family members (An account by such a debtor). As such, Newgate was a mixing ground for the upper class, lower class, and the nouveau-rich members of the newly formed middle class.
Throughout most of the eighteenth century, London had no government-run police force. Theoretically, the enforcement of the law was the responsibility of unpaid constables, church beadles, and the "Charlies," or night watchmen. None of these groups was up to the task of enforcing the law in the increasingly lawless environment; for that matter, none were particularly inclined to attempt the task. The solution hit upon was, essentially, a bounty system, with a large monetary reward(£40) being offered to anyone who brought a criminal to conviction. This system created a group of "thief-takers," private citizens (often criminals or former criminals themselves) who hunted down and secured the convictions of criminals on the behalf of the victims. The most famous (and most corrupt) of these was Jonathan Wild.