I'm going to use the fact that my ex-friend beat someone to death to get leverage at school
Why do you need to get leverage?
I want to be the center of attention again
It is wrong to spread rumors to be the center of attention. You should respect peoples privacy if they don't pose a danger to others.
I know I'm just worried that people don't care about me.
Hurting other people to get attention is wrong, you could really hurt people and their reputations. If you feel people don't care for you you should try talking with a therapist about your insecurities.