its sad. if a black man wore a gun like that in georgia, the police would shoot him on sight, even if he wasnt pointing it at anybody.
Please go back to Huffington Post.
The term Assault rifle goes back to WW2 with the one of the first successful rifles of it's kind known as the Sturmgwehr Rifle and supposedly Riddler came up with the term. The idea was to create a gun that could be used in close quarters with the of fire of an smg and have the accuracy of a rifle. They also had to fire an intermediate cartridge, basically something smaller than a rifle caliber and larger than a pistol caliber. Full auto is optional, it is a useless ammo wasting feature that no one uses in real life.
However words like Assault rifle, sniper rifle, and hunting rifle just define how the rifle should be used. For example take the Springfield for example

Military rifle in it's day, but you can find many bolt action rifles that are very similar to it. It's just a rifle. However when we put a scope on it

it is now known to the movie an video game world as rifle or as a hunting rifle because I am hunting for food with it. To be honest you can still be a marksman/sniper without a scope just like Simo Häyhä. Even in the military a rifle is just a rifle, everything else is just a noun.
The media the could the people were attacked by a person with a rifle, however when they say people were attacked by a armed shooter with a sniper rifle/assault rifle more heft is added to the message and creates more interest and public reaction.
The AR15s that people have are meant for the civilian market. If you want a machine gun or a full auto rifle you have to pay a tax stamp and register your firearm to the ATFE as part of the NFA and notify the nearest law enforcement agency, usually the county sheriff.
Watch this for evidence:
https://www.youtube.com/watch?v=BKGZnB41_e4&feature=youtu.be&t=25s
He didn't say it was guaranteed. He said it happened in general.
That video... There were more cops in this video surrounding some old white guy
https://www.youtube.com/watch?v=9Ap4reNEbyQ