Clever in deducing the unknown from the known, he excelled in collecting facts, and in uniting in a bundle of overwhelming proofs circumstances the most trifling, and in appearance the most insignificant.
Although possessed of qualifications for his office so numerous and valuable, he was tremblingly distrustful of his own abilities and exercised his terrible functions with diffidence and hesitation.

He wanted audacity to risk those sudden surprises so often resorted to by his colleagues in the pursuit of truth.
Thus it was repugnant to his feelings to deceive even an accused person, or to lay snares for him; in fact the mere idea of the possibility of a judicial error terrified him.

They said of him in the courts, "He is a trembler." What he sought was not conviction, nor the most probable presumptions, but the most absolute certainty.

No rest for him until the day when the accused was forced to bow before the evidence; so much so that he had been jestingly reproached with seeking not to discover criminals but innocents.
The chief of detective police was none other than the celebrated Gevrol.
He is really an able man, but wanting in perseverance, and liable to be blinded by an incredible obstinacy.

If he loses a clue, he cannot bring himself to acknowledge it, still less to retrace his steps.