Scary confusing dream

I have these very weird dreams sometimes. I love dreaming. My mind comes up with the most surreal things sometimes. Sometimes I am in the dream, sometimes it is as if I am watching the dream unfold from the sky like an observer.

In this dream however, I am present.

I am at this building and there is a murderer walking around killing people. The murderer has a big knife, and to kill people he/she slashes a + sign all over a person’s face. It is not graphic. Not gory. No blood. I can’t describe exactly how that looks.
In the dream I am walking through the halls of the building, trying to get out of there before he/she finds me. I am sneaking down a corridor and when I turn around a corner, I am right behind the murderer. The murderer kills the person right in front of him/her and then slowly turn around to face me. I freeze and when our eyes meet, me as in the dreaming me, shifts the person I am in the dream, so suddenly I am the murderer and kill the person that was just me. If that makes sense.

Anyone have any idea of what that might symbolise?

This shows that you were seeing yourself in the dream. This could relate to how you deal with people in real life. The dream could imply judgment. Do you tend to pegion hole people in real life? Sort of like the mark of "Zoro" in those old movies.

Facing your inner demon. could be a realization like thunder bow said.. or if you have been long trying to escape/ battle outside negativity... maybe feeling that you are trapped in a defensive loop that is wearing you down to the point where you either fear that they are right or feeling it might just be easier to give in to thes doubts or opinions and allow then ( worst you) to slay ( true you)..then to keep on fighting.

I like your positive additional input.