"A woman came in here just last week and bought that knife. That ebony handle makes it one of my most expensive, but she didn't care about price. She asked about the address of some hotel, I'd never heard of it though."
―Pinson upon being questioned by Arno Dorian, 1793.[src]

Mathieu Pinson was a merchant in the Sorbonne district of Paris who specialized in knives, daggers and swords. His shop was located on 5 rue Haute Feuille.

In July 1793, the Girondist sympathizer Charlotte Corday planned to assassinate the leading Jacobin politician Jean-Paul Marat. She bought an expensive ebony handle kitchen knife from Pinson, who noted that she was not concerned about the price. Corday also asked for the address of the Hotel Providence, of which he had never heard.

After Marat was killed with the knife, Arno Dorian investigated the murder. Checking the maker's mark of the knife, he found Pinson at his shop, who told Arno of his encounter with Corday.