Casey's disappearance had crystallized the suspicions into an immediate investigation.

And Barney's assertion that Casey had been murdered took the coroner along with the posse.
It had all been straight and fairly simple until they reached the mine and discovered Casey uproariously one of the gang.

Throwing loaded dynamite at sheriffs is frowned upon nowadays in the best official circles, I told Casey; he would have to explain that in court, I was afraid.
Then Barney, after Casey had kicked him in the chin, had reversed his first report of the trouble and was now declaiming to all who would listen that he had been decoyed to Black Butte by Casey Ryan and there ambushed and nearly killed.

Casey, as Barney now interpreted the incident, had joined his confederates under the very thin pretense of climbing the butte to come at them from behind.

Barney now remembered that he had been shot at from three different angles, and that the burros had been killed by pistol shots fired at close range--presumably by Casey Ryan.
It was like taming tigers to make Casey sit still and listen to all this, but I had to do it so that he would know what to disprove.
Afterwards I had a talk with Joe and Paw, separately, and so got at the whole truth.