The preliminary hearings started on February 4, 1880 at McLean's Hotel in Lucan, Ontario. There were three preliminary hearings leading up to the first trial in October 1880. In between the preliminary hearings and the trial, there was a change of venue request, which was ultimately rejected. The crown felt that a fair trial could not be obtained in Middlesex County, as it was too biased against the Donnellys. One of the key witnesses for the prosecution was Johnny O’Conner, who had witnessed the whole massacre. The vigilantes did everything in their power to try to keep Johnny from testifying. Michael O’Conner, Johnny's father, owned two houses on Francis Street, in Lucan. One of the houses was known to have run a bootlegging operation at times, the other house he rented to Bob Donnelly. During the late evening of April 13, the vigilantes burnt the house of O’Conner to the ground. The vigilantes harassed not only the father, but also Johnny's mother, Mary: while she was in London, on one occasion when she passed Patrick "Grouchy" Ryder on the street, he threatened and insulted her. She laid a charge against him of using abusive language. At his court appearance, fellow vigilantes swore that he was in Biddulph at the time of the alleged infraction, and this led to his discharge. Young Johnny was not deterred from testifying by any of the group's activities.