Popular Library G-451 (June, 1960). Reprint edition. Cover Art by Schaare

From the back cover:

 

Fargo was his name, and somehow he'd never learned to tip his hat to a killer . . . even on orders from the biggest man in the territory.

 

So they framed him for murder, then watched him escape. And on the trail they knew he'd take they stationed a killer . . . who lived by the creed that dead men never prove their innocence.

Done