To dream of violence or a violent act is meant to remind you of anger that you have tried to hide from those around you. It is likely that your life lacks structure and discipline. A dream in which violence is prevalent may also indicate memories of child abuse that you have locked away.
I dreamed that I was in a huge building flooding and I started killing people, but saved children who where trapped inside, in the last room a man sat on the floor and I stabbed him in the back, turned him round strangled him, can’t tell who any of the people where. Also I dreamed I was a serial killer, every word you can think of I was, then I went to a forest and hanged myself, then I was this dead person, watching the police and swat force around my dead body.