'Good Samaritan' citizen had gun under state's constitutional carry law when he stopped mass shooter

The "good Samaritan" who drew his weapon and ended a deadly mass shooting at an Indiana mall on Sunday was reportedly carrying his firearm under the state's new "constitutional carry" gun law. 

"Constitutional carry" refers to a type of law passed by multiple state legislatures that allows citizens to carry guns without first obtaining a concealed carry permit. Half of all U.S. states now have some form of constitutional carry provision on their books. 

Local news station WTHR reported this week that the citizen who stopped a mass shooting in Greenwood, Ind., on Sunday was carrying a gun under the state's just-instituted constitutional carry rule. 

Elisjsha Dicken "had no police training or military background," the network reported; meanwhile, he was "carrying under the new 'Constitutional Carry' law and did not have a permit."

Dicken reportedly learned to shoot his firearm from his grandfather, according to police. 

The hero fired 10 rounds at the shooter after the incident began, striking the killer as he tried to retreat.

Greenwood Police Chief Jim Ison called Dicken's actions "nothing short of heroic" and said he was "very proficient" in the use of his handgun.