Tokacou, or He That Inflicts the First Wound, was a member of the team of "warriors of high repute" as McKenney described them, that were organized in every Yankton Sioux village to mantain discipline and to carry out the decrees laid down by the council.

This primitive yet effective law and order group punished habitual offenders by cutting their blankets to shreds, killing their hunting or war ponies, slashing their tepees, smashing their rifle barrels, or snapping off the blades of their invaluable hunting knives.

Summary execution was also within their power; only outstanding warriors were above the so-called "soldier-killing."

Colonel McKenney described Tokacou and his fellow soldier killers as strict disciplinarians whose "authority is greatly respected by their people. This is especially observable on the arrival of a white man, or a party of whites, at their village. If these persons take the strangers under their protection, no one presumes to moleste them: if the sword or the war-club of one of them is seen at the door of the white man's lodge, the sign is well understood, and no Indian ventures to intrude."

Tokacou signed treaties for the Yankton Sioux at Fort Lookout, June 22, 1825; Prairie du Chien, July 15, 1830; and one in Washington, October 21, 1837, when the Sioux chief was painted holding his sword of authority.