Or, to get at it another way, here is a miscellaneous list from my own notebook of possible motives for murder: financial gain, self - protection, to preserve status, fear, to protect a loved one, for a principle, for revenge (but remember credibility here: only in some societies is revenge stoked up enough to lead to killing), the drive to power, compensation for past humiliation, removing a bar to sexual happiness (bother the permissive society, but impediments do still exist), jealousy, the desire to cock a giant snook at the whole world.
Or, to get at it another way, here is a miscellaneous list from my own notebook of possible motives for murder: financial gain, self - protection, to preserve status, fear, to protect a loved one, for a principle, for revenge (but remember credibility here: only in some societies is revenge stoked up enough to lead to killing), the drive to power, compensation for past humiliation, removing a bar to sexual happiness (bother the permissive society, but impediments do still exist), jealousy, the desire to compliment at the whole world.