Who the hell was the a$$HOLE who called the cops and said there was a man with a gun? No gun! This is the kind of mad hysteria that gets people killed!
It does not really matter what the caller said. They could have said that it was a man from Mars. When the policeman arrived on scene, he should have had two eyes that he could see with. Now if the Officer was blind, if would be a different story. If the Officer knows what a firearm looks like, his eyes could have informed him[the officer] whether the man had a gun in a position to use it or not. The Officer should be charged with attempted murder.