Showdown in Sonora [and] The Manhunter by Gordon D. Shirreffs (1995-09-01)

A young killer is on the run, chased by two separate posses bent on hunting the Yankee gunslinger down. But the only real threat to the outlaw came from a bounty hunter named Lee Kershaw who had taught the young desperado everything he knew. Nothing could stop Kershaw from catching this man--even the danger that, when he caught up with the kid, it might be the end for both of them.