a good reason

"When he gave us our air-rifles Atticus wouldn´t teach us to shoot. Uncle Jack instructed us in the rudiments thereof, he said Atticus wasn´t interested in guns. Atticus said to Jem one day" I´d rather you shot tin cans in the back yard, but I know you´ll go after  birds. Shoot all the bluejays you want, if you can hit 'em, but remember it´s a sin to kill a mockingbird"
That was the only time I ever heard Atticus say it was a sin to do something, and I asked Miss Maudie about it. "Your father ´s right" she said. "Mockingbirds don´t do one thing but make music for us to enjoy. They don´t eat up people´s gardens, don´t nest in corncribs, they don´t do one thing but sing their hearts out for us. That´s why it´s a sin to kill a mockingbird."


To kill a mockingbird - Harper Lee