M. Taboret was called Tirauclair because of his habit of saying that things must be "brought to light".
Some time before Mr. Holmes, M. Tirauclair was able to reconstruct a crime scene very accurately just from keen observation of the evidence at hand. No DNA, no fingerprints or blood samples, but he did very well without these conveniences. Like M. Poirot, he relied on his "little grey cells". I think he was featured in only one novel: The Lerouge Affair by Emile Gaboriau. Because of his acuity, his acquaintances called him Mr. Bringtolight.