I Have These Really Violent Urges And I Don't Know

I have these really violent urges and I don't know what to do about them I feel like just killing someone anyone sometimes even a specific person I have noticed I have a lack of empathy I try telling someone but they think I'm using it as an excuse to get away with things sometimes I feel like just taking actions into my own hands and these urges don't stop I'll be sitting and watching tv and my mind will wonder off and I'll just think of these things