Atticus has always advised his children to be tolerant of other people's opinions--to
"... climb into his skin and walk around in it."
Following the attack by Bob Ewell on Atticus's children, Sheriff Tate is quick to realize that it is Boo Radley who has come to their rescue--and killed Bob in the process. Sheriff Tate recognizes that Boo has done "this town a great service" by killing Bob, and that it would be "a sin" to force Boo, "with his shy ways into the limelight" of a public investigation or trial. Tate is unknowingly following Atticus's advice by placing himself in Boo's shoes and foreseeing the consequences of his actions. His decision to call Bob's death self-inflicted may not be an honest one, but it preserves the innocence of the human mockingbirds--primarily Boo, but also Jem and Scout--and keeps them from the scrutiny and gossip of a public inquiry.