The following is based on Van Buren and has not been confirmed by canon sources.
Half-brother to Frieda Van Graff and one of the escaped Tibbets prisoners, Jean-Baptiste was to play a fairly major role in the first act of Van Buren, but was only ever mentioned in Frieda's biography.
In Fallout: New Vegas, Cutting has taken on the role of an enforcer, becoming the backbone of the Van Graff family security forces. He works in the Silver Rush alongside his half-sister, Gloria, and does his part in the politics of their operations in the only way he knows how; with the barrel of his laser rifle. He has Cutting as a surname, opposed to Van Graff because his mother only gave him the surname to remind herself of her dead husband, who was also Jean-Baptiste's biological father.
Jean-Baptiste Cutting has high health, more than most companions, as well as an incredible, and normally impossible, 117 Energy Weapons skill. The only reason for this seems to be to make him a "boss" character. Despite that, he is still fairly easily defeated at higher levels if needed in Tend to Your Business.
While armed with a laser rifle, he will usually pick up the plasma caster in the middle of the store if engaged in combat, unless it was previously stolen by the player.
During Birds of a Feather, when he confronts Cass and shoots her, he might shoot the floor or ceiling and Cass will still die. This is likely due to the fact that he is one of the only NPCs in the game that is fixed to kill another NPC by his own actions (i.e. through a quest)