The case of the parties to this most diabolical conspiracy immediately received the attention of the law officers of the crown; and on the 15th April 1820, a special commission having issued, the prisoners were arraigned at the bar of the Old Bailey on the charge of high treason, and also of murder, in having caused the death of the unfortunate Smithers. There were eleven prisoners, Arthur Thistlewood, William Davidson (a man of colour), James Ings, John Thomas Brunt, Richard Tidd, James Wilson, John Harrison, Richard Bradburn, John Shaw Strange, James Gilchrist, and Charles Cooper, and they all pleaded Not guilty to the charges preferred against them. Counsel having been assigned to the prisoners, and the necessary forms having been gone through, Thistlewood received an intimation that his case would be taken on Monday morning the 17th of the same month, and the prisoners were remanded to that day. At the appointed time, accordingly, Arthur Thistlewood was placed at the bar. He looked pale, but evinced his usual firmness. The jury having been sworn, and the indictment read, the attorney-general stated the case at great length, and twenty-five witnesses were examined in support of the prosecution, among whom were several accomplices, whose testimony was satisfactorily corroborated. Some of those who appeared to give evidence had been apprehended on the fatal night in Cato-street, but were now admitted witnesses for the crown. After a trial which occupied the court four days, Thistlewood was found Guilty of high treason. He heard the verdict with his wonted composure, seeming to have anticipated it; for when it was pronounced he appeared quite indifferent to what so fatally concerned him. The evidence against Tidd, Ings, Davidson, and Brunt, whose trials came on next in succession, differed little from that upon which Thistlewood was convicted, and they were also found Guilty. Their trials being separate, occupied the court six days. On the evening of the tenth day the six remaining prisoners, at the suggestion of their counsel, pleaded Guilty, having been permitted to withdraw their former plea, by which they eventually escaped capital punishment. On Friday, April the 28th, the eleven prisoners were brought up to receive sentence. When the usual question was put to Thistlewood by the clerk of arraigns, why he should not receive sentence to die, he pulled a paper from his pocket, and read as follows:--