If the law had not been replaced or abolished it was still in effect. And a law which d'Enghien violated and what he was convicted on has already been given to you. And France was at war with Great Britain and d'Enghien in the pay of the British government when he was taken, tried by competent authority, and executed. So it was a time of war, not peace.
D'Enghien was taken on 15 March 1804 and tried and executed almost a week later on 21 March 1804. France and England had been at war once again since 18 May 1803 when Britain decided on war and began to take French shipping.