The government of Adolphe Thiers charged Lecomte with retrieving cannons from Montmartre where the National Guard had brought them when the Prussians had advanced on the Champs Elysees.

General Lecomte and the officers of his staff were seized by the guardsmen and his mutinous soldiers and taken to the local headquarters of the National Guard at the ballroom of the Château Rouge.

In the middle of the afternoon Lecomte and the other officers were taken to 6 Rue des Rosiers by members of a group calling themselves The Committee of Vigilance of the 18th arrondissement, who demanded that they be tried and executed.

Minutes later, another general, Jacques Leon Clément-Thomas, who was in civilian clothes, having reconnoitered the barricades of Montmartre, was recognized by the crowd, thrown on top of Lecomte's corpse, and slain in turn.

On 18 November 1871 a court-martial (le 6e Conseil de Guerre) handed down the death penalty to Simon Charles Mayer (1820 Nancy - 1887 Basel), major of the Paris Commune, for being responsible for the murder of the two generals Claude Lecomte, and Jacques Leonard Clement Thomas, in spite of weak evidence.