absolutely! i have WAY to much experience with this stuff. If you are curious about it look in to the power of blood. ALL cultures of ALL times have understood these things. look into some of aleister crowley's teachings on the stealing of innocence. You may not believe in evil spirits but these people do and they are real. these people worship and serve them. The more innocent blood that is spilled the stronger they become.
BUT the power of LOVE is stronger than any stupid evil bastard (whether spirit or human). I have seen this too.