I would like to know what my rights are . . . it's long?

I work retail at a store in a mall and a gay rights activist who stands outside the store has been haring me. ( I have no problem with gay people, I have even donaited to her cause) She started off by comming into the store and insulting the me aswell as the other employees. The next day she did the very same thing, so my boss called mall security to get her remmoved from the front of our store. As a result she to told my boss she was going to kill her. My boss got her fired from her company but another company hired her and she was put back infront of our store. Here is where she gets really crazy. I left one day on my break while she was talking to someone, while i was walking back to the store I noticed she was fallowing me. She started saying things like "you better watch your back" and "I'm going to get you". At this point I told my boss who called the company she works for but they said they didnt believe us and she remained there. Today I went to the mall just shopping and she spotted me and proceeded fallowed me along with my boyfriend and cousin. When I sat down at a table she approached me and threatened to kill me. In addition, she said she was going to go into my work tomorow and physically ult me, so we both get fired. I don't know what to do about her. Do I have any kind of legal grounds and if she does hit me what will happen?