The aim of this article is to investigate the relationship between professional magistrates and laypersons in Italian criminal justice under the Fascist regime. The reform of the courts of assize, approved in 1931, abolished the jury trial and introduced a system based on cooperation between professional judges and laymen assessors. The two components of the bench had to work side by side and decide on the innocence or guilt of people charged with serious crimes. This forced collaboration resulted in the phenomenon of “suicidal sentences”. The case of Francesco Mulas, accused of murder and robbery, is the most famous example of a conflict that could lead to fatal consequences. This paper seeks to analyse the reasons of this contrast and the remedies elaborated by eminent legal experts.