Is it normal to have frequent thoughts about homicide, rampage?

There are times and hours during the day in which my head fills with various things related to psychological and especially physical,bodily (More achievable with lower IQ since the psychological part requires good brain) and then after for no apparent reason, total relief and remission from these thoughts, in which i feel more serene, except other non violent or not necessarily wanted, intrusive thoughts of causing harm to unwanted group of people, or the ones close to me.