Murder can happen for a variety of reasons. Some murder for fun. Some do it because they can’t help themselves due to a mental issue. Others do it by accident and there are other that plan the murder out. Then there are those that happen out of pure jealousy. When someone sits and thinks of an ex-lover moving on or a current lover cheating or getting ready to leave them, something in their mind snaps. That is when they will purchase the weapon of choice or go find the person they intend to do harm to and use what they can find to commit murder.