Meaning of dreaming of murdering someone depends on the situation and time as per dream interpretation. If the dream was seen during early morning hours then it means you will soon overcome an emotional or stressful situation. If you see red color during the dream of murdering someone then it means trouble in a relationship.
Dreaming of murdering someone usually happens when you have intense hatred in your mind. The dream is a suggestion to change your thought process. The dream also means in near future your anger will cause disruption to your life.
If you happen to dream of murdering someone in a crowd it means some kind of accident. It also means you might hurt someone unintentionally.
If you dream of murdering someone you know then it means there will problems in relationships and your anger might cause some severe damage to your life.
Today movies, social media and other visual and print media glorify murdering etc. You should not fall for it. Too much viewing and listening to such things result in such dreams. And such dreams have no meaning.