Lemaitre was a politician of the French Revolution.

A deputy of the Legislative Assembly, Lemaitre played a part in overthrowing the Girondist government of France. His pride in this was so great that he sought the head of executed Girondist leader Jacques Pierre Brissot.

To this end, he worked with LeNôtre, a military captain who had been in love with the executed Girondist Olympe de Gouges and wanted her head. Together, they acquired the heads and had them placed in chests in the Conciergerie. In 1794, however, the key to the chests was stolen by the Assassin Arno Dorian. Arno recovered the heads and took them to Marie Tussaud, a sculptor charged with creating death masks of famous victims of the guillotine.