The Judge and His Hangman (German: Der Richter und sein Henker) is a 1950 novel by the Swiss writer Friedrich Dürrenmatt.

A new translation by Joel Agee appeared in 2006, published together with the book's sequel, Suspicion, as The Inspector Bärlach Mysteries, with a foreword by Sven Birkerts.

Commissar Bärlach of the Bernese police, who is dying of cancer, must solve the murder of his best officer, Lieutenant Ulrich Schmied.

They had long ago made a personal bet with one another as to whether it was possible to commit the "perfect" crime, such that even an investigator who witnessed it would never be able to prove the perpetrator guilty.

After that bet, Gastmann, as Bärlach well knew, had pursued a lifelong career as a purveyor of crime, evil in its comprehensiveness, arrogant and mocking of civilisation itself.

Lutz, the university-educated overseer, insists on the efficacy of modern, scientific crime-solving methods "from the Chicago school", which is based mainly on circumstantial evidence and forensics.