 After several thorough interrogations, however, he was handed over to the authorities with Julchen and some accomplices on 16 June 1802 and they were taken to French-occupied Mainz.After being handed over, Bückler was imprisoned in the Wooden Tower of Mainz and subjected during the 16-month preliminary investigation by Johann Wilhelm Wernher to several dozen individual interrogations, during which 565 questions were asked.In addition, there were numerous identity parades.