On to kill a mockingbird, Where is the Sheriff and why can’t he help Atticus

In Chapter 10, a rabid dog by the name of Tim Johnson is staggering down the middle of the street in Maycomb. When Sheriff Tate arrives, Atticus tells him that he better take the shot while Tim Johnson is standing in front of the Radley gate before the dog wanders down a side street. Sheriff Tate hands his rifle to Atticus and tells him to take the shot because it is a "one-shot job." Atticus is reluctant to take the rifle, but Tate insists. Atticus takes the gun, raises the rifle, and shoots Tim Johnson right above his left eye, successfully killing the rabid dog. Mr. Tate smiles and says, "You haven't forgot much, Mr. Finch. They say it never leaves you" (Lee 128). Then, Miss Maudie says, "I saw that, One-Shot Finch!" (Lee 128). After Atticus drives away with Sheriff Tate, Maudie tells the children that Atticus' nickname was "Ol' One-Shot" when he was a boy (Lee 129)

that’s a nice boss :