Marie was tracked down to
Edinburgh, where she was caught after trying to exchange some of O'Connor's property (a listing of his possessions had been published). The ten certificates of shares of the
Huntingdon,
Wisbech, and
St. Ives Railway were found in her possession. Elsewhere, Frederick was caught on the island of
Jersey. They were tried at the
Old Bailey on 25 and 26 October 1849. The trial was not one of the most fascinating in terms of legal problems, except that it was argued that the jury had to include people of French or Swiss ancestry in fairness to Marie. O'Connor's stockbroker, Francis Stevens, gave evidence identifying the railway shares: "I know them by the numbers, and by my initials. I delivered them on the 6th of August last. They are amongst the advertised shares, and are numbered 6,460 to 6,469" He also identified ten
Amiens and
Boulogne shares, numbered 48,666 to 48,674 inclusive, supplied to the deceased. During the trial, Frederick said that he "never liked [O'Connor] very much". Both he and Marie were found guilty and sentenced to death by
hanging, Marie yelling imprecations at the British as a 'perfidious race'. The couple were reconciled shortly before they were executed by
William Calcraft at
Horsemonger Lane Gaol on 13 November 1849, where they were then buried. A
death mask of Marie was acquired by Dr Thomas Grierson for his Thornhill Institute in
Dumfries then in 1965 by
Dumfries Museum on the dispersal of Grierson's collections, whilst the couple's grave markers were rescued for the
Cuming Museum on the Gaol's demolition in 1881 and remain in the collection of the Cuming's successor the Southwark Heritage Centre. ==Reaction==