He did not need a warrant.

What he had seen was his warrant--plus the shotgun.
As a "pathfinder" should, he planned to take up the trail where he had lost it, but, before he reached Round Hill, he found a warmer trail.
Before him, stamped clearly in the road still damp from the rain of the night before, two lines of little arrow-heads pointed the way.

They were so fresh that at each twist in the road, lest the car should be just beyond him, Jimmie slackened his steps.

After half a mile the scent grew hot.

The tracks were deeper, the arrow-heads more clearly cut, and Jimmie broke into a run.