He was, however, soon afterwards again discharged out of custody, the money being retained in the hands of the bankers. In 1815 he resolved to recover the bills and drafts from the magistrates, by whom they had been taken from him; and as they refused compliance with his request by letters, he visited Glasgow in person, and demanded, in the most insolent manner, the restitution of what he called his property. This being refused, he commenced an action against them, which, more than any other case that ever came before a court of justice, proves the glorious uncertainty of the law; for it continued to be litigated for five years; and, the bankers having become the defendants, the country, for the first time, witnessed the singular fact of an acknowledged thief contending with persons for the property he had actually stolen from them. During the progress of this protracted case, Mackcoull attended the courts of law in person, and gave instructions to his agent. He always conducted himself with the greatest _sang froid_, and treated with contempt and derision the allusions made by counsel to his character. At length it was ruled that Mackcoull should be interrogated in person before the court; and after some hesitation he consented. This circumstance was no sooner known, than crowds flocked to hear his examination, which lasted for several days. He behaved in the most cool and determined manner; and when his absurd replies elicited a laugh in court, he always smiled with seeming self-approbation. The account he gave of himself was that he traded as a merchant, and that he chiefly transacted business with one James Martin, whose residence he could not tell. He objected to many questions put to him with the acuteness of a lawyer, and at length the session rose without having come to any decision; and Mackcoull returned to London in great spirits, to arrange with his brother John with respect to his future proceedings. The bank was at this time in a critical situation: unless they proved Mackcoull's participation in the robbery, and that the bills &c. were purchased with notes stolen from the bank, they would have to deliver up to Mackcoull not only the bills, &c., but to pay all attendant expenses, besides incurring the disgrace of losing the action--an action unparalleled in the annals of any court of Europe, brought by a public depredator--a convicted rogue and vagabond--who was at large, and who was prosecuting with their own money a respectable banking company, for attempting to keep part of the property of which he had robbed them. But this was not all. Mackcoull's intention, if successful, was to follow up the decision with an action for damages, in which it was the opinion of many that he would also succeed. In December 1819, Mackcoull and his agent urged the matter so strenuously, that the trial was fixed for the 20th of February 1820; and the issue to be tried was, whether Mackcoull was concerned in the robbery.