Simenon's The Man on the Eiffel Tower (1949).

In The Man on the Eiffel Tower, impoverished medical student Franchot Tone is hired to kill a man's rich aunt. Also featured are Burgess Meredith, Charles Laughton (as Maigret), and Wilfred Hyde-White, with directing duties taken by Meredith, Laughton, and Irving Allen. The film is adapted from Georges Simenon's A Battle of Nerves (aka War of Nerves).