[2] During his career as a lawyer, he achieved fame in both the public and legal spheres in 1938 after he represented the defendant in what was dubbed the "Chinese restaurant massacre" case.

The case involved the murders and attempted robbery of 4 people, the owners of a Chinese restaurant in São Paulo and two of their waiters, as part of a revenge plot by a maltreated former employee, Arias de Oliveira.

Lauro went on to oppose much of president Jânio Quadros' policies as a member of Congress, contributing to the turbulent political climate that led to his resignation.

He also opposed the normalization of relations with the Soviet Union by Quadros' successor João Goulart, as well as further state intervention in public utilities.

After the 1964 Brazilian coup d'état and the establishment of the military dictatorship, he became a member of ARENA and ran again for Congress in 1966, but was not elected.