Roche displayed intrepidity and spirit in his military doings, and was expected to rise to a high rank until an unfortunate event destroyed his career. An officer of Roche's regiment missed a valuable gun, which was later found in Roche's possession. Roche declared that he had bought the gun from a corporal of the regiment named Bourke. Bourke declared on oath that Roche's statement was false, and Roche was brought to a court-martial. Roche was convicted of the theft and ordered to quit the service with "every mark of disgrace and ignominy".