My hypothesis is that if the stand your ground law is passed, and there are more murders, there should be more visits to the emergency room due to gun inflicted wounds. See below for information:

Visits to the ER

Of those who passed the law, Arizona (2006) saw a decrease, Florida (2005) saw a slight decrease, Kentucky (2006) saw a slight increase, North Carolina (2011) is ambivalent, South Carolina (2006) saw an increase, Tennessee (2007) saw a decrease. So out of 6 states, three had a decrease and two had an increase.

Among the states who did not pass the law, Hawaii had a decrease, Illinois doesn’t have a distinct trend, Iowa no trend, Maryland had a large decrease, Minnesota decreased, Nebraska doesn’t see much change, New Hampshire had a decrease, Utah had a decrease, and Vermont also. So among 9 states, five had a decrease and none increased.