I found both of these news reports of armed robberies on the same news website. You’ll note the difference in result for the business owner when he was armed!
First, this is what happened with an armed business owner was robbed by FOUR CRIMINALS at his auto repair shop:
http://www.myfoxhouston.com/dpp/news/local/091210-robbery-suspect-fatal-shooting
Then, this is what happened in the People’s Republic of Chicago when an unarmed business owner was robbed at another auto repair shop:
http://www.myfoxchicago.com/dpp/news/crime/Business_Owner_Shot_During_Robbery?obref=obnetwork
QUITE A DIFFERENCE!