Streets of Laredo (TV Miniseries)

Captain Woodrow Call, now retired from the Rangers, is a bounty hunter. He is hired by an eastern rail baron to track down Joey Garza, a new kind of killer, only a boy, who kills from a distance with a rifle. Joined by his old compadre Pea Eye, it is a long ride to south Texas and the Mexican side of the border, where the past, in the form of Maria Garza, Joey's mother, haunts Call.