Second Amendment? Man Arrested After Reportedly Firing Warning Shots To Save Woman From Robbery (Video) - Red State Nation
The vigilante arrested for opening fire during a robbery attempt in a Manhattan subway station yelled “Get away from her!” at the would-be mugger — just before he pulled a pistol from his backpack and sent a couple rounds flying down the platform, sources ...
The article doesn't go into great detail, but mentions "criminal possession of a firearm", so he may not have even had a permit for the gun.
He wanted to help,but he didn't think it through about how his actions could impact his life. I gather in a place like NYC, you have to be very careful if you choose to intervene in a situation like that.