He was born in Reims and educated at the Faculty of Law of Paris.

[1] In his professional life he defended the accused in some of the most prominent political cases of his day.

Among his noted clients was Alfred Dreyfus who was eventually acquitted of treason.

During the Dreyfus trial, Labori was the victim of an assassination attempt which hospitalized him for a week and the attacker was never identified.

[2] Labori was elected second secrétaire de Conférence du barreau de Paris and he was the defence counsel for: His speeches were regarded as masterpieces of forensic eloquence.