Sure they can. "You have the right to free food, cell phones, and medical treatment, all paid for by other people whose guns you want banned."There is not enough information in the short snipit of info I saw to make a determination. The problem is the way it is spun by CNN. With just the information that he had a gun, they assume people think that is reason enough to arrest him. Most of the sheeple know all the lyrics to Lady Gaga's last song but can't name 1 amendment from the Constitution.
Not sure which amendment it is, but it's got to be in there, judging by the state of things.