Pierce agreed, then reneged around mid-1856. Desperate for money, she went to see John Weatherhead, the governor of Newgate Prison, and told him that she knew who was involved in the SER bullion robbery. An investigation was undertaken at Cambridge Villa; police found evidence that corroborated Kay's story, including the burnt floorboards, small specks of gold in the fireplace and under the floorboards, and evidence that the fireplace had been used at a very high temperature. Agar was interviewed in October 1856, while still in Pentonville, by John Rees, the company solicitor for the SER; Agar refused to answer any questions, and so Rees returned around two weeks later and tried again. In the interim, Agar had heard that Pierce had not kept to his word and so, angered by the deceit of his erstwhile partner, he turned Queen's evidence and gave Rees the full details of the crime. Pierce and Burgess were arrested on 5 November. As Tester was living in Sweden he could not be arrested, but he was informed that the police wanted to interview him. Legal process In November and December 1856 hearings took place at the Mansion House, presided over by the Lord Mayor of London in his role as the Chief Magistrate of the City of London. For the first two hearings, Agar was not present, but was brought to the court on the third day. When questioned, he confirmed the story he had given to the police, and identified pieces of evidence that had been gathered. On 10 December Tester appeared in court, having been dismissed from his position with the Swedish company. When the Lord Mayor gave his decision on 24 December that the three men were to stand trial for the robbery, Pierce said "I have nothing at all to say. I reserve my defence." Burgess and Tester both stated "I am not guilty". The trial took place at the Old Bailey between 13 and 15 January 1857, and received wide coverage in newspapers across Britain. Burgess, Tester and Pierce all pleaded not guilty. Agar gave evidence against his former colleagues again, and told the court he was, in Thomas's words, "a self-confessed professional criminal who had not made an honest living since the age of eighteen". Witnesses included the locksmith John Chubb, the bullion dealers, transportation agents, SER staff, the station staff of London Bridge and Folkestone, a customs officer