What are the top motives for murder?

Here's a simple formula for you:

Crime = Opportunity * Motive

Basically, if you want something bad enough and have the chance to achieve it, you will [attempt to] get it. I say attempt here because, in all likelihood, you might screw up and get caught/stopped. But that doesn't stop more than 500 million crimes per year occurring, ranging from petty theft to serial murder.

Here are some of the most pressing motives for murder:

  1. Money.
    According to Times Magazine, most couples believe money is the most important factor in a good marriage. Incidentally, this is also the number one motive for divorce.
  2. S*x
    I don't think an explanation is due here, but the sexual urge for a woman/man is often times enough to outweigh their last shred of dignity. Vicious love triangles, rape, the whole lot...
  3. Killing out of "mercy"
    Not as bad as plain murder, but still a violent action... just as the old joke goes:
    A man is driving his tractor down the steep hill with his pig and dog when the tractor flips, injuring the 3 very badly. By and by, an officer comes around, and sees the pig very hurt, and puts it out of misery with a shiny tokarev m57. His dog meets a similar fate. And so when the officer reaches the man and asks if he is in much pain, despite 3 broken ribs, a broken wrist and ankle, his immediate response is "Never felt better, sir!"
  4. Revenge
    I can't believe you slaughtered my dad 45 years ago this day to keep him from winning the Nobel prize... I can't let you live anymore
  5. Greed in general
    Nice watch, mate...
  6. Self Defense
    Wanna come to my house for the night..?
  7. Conflicting opinion
    Be it political, religious or cultural, these days it seems no one can agree on anything...
  8. Drugs/alcohol/smokes
    Hey, ya got mah hooked on meth, I canna just go cold turkey
    *pulls safety guard off gun*
  9. Serial/Pointless
    As sad as it is, there are cruel, heartless souls (lawyers?) who will kill for the thrill of killing.
  10. Power
    The ruler of England, local governor, hot dog master, you've heard it all. Some people will do anything up to murder to get in the news as a powerful leader.

And that's it. Hope this didn't inspire you (seriously, my life depends on it)!

It's not exactly a motive, but I believe you need to include "alcohol and drugs" in the list.  They exacerbate all the other motives.

Many violent crimes are committed on impulse, and you might as well be asking a question about quantum physics if you were to ask the perpetrator why he or she did it. The most common reasons that people commit pre-planned, calculated murders, are for love or profit--often both.

In my practice, I hardly ever asked a client why he or she committed the charged crime. It wasn't something I needed to know for my defense in most circumstances. It may become relevant later, if a conviction results, to mitigate the sentence, but there are really very few reasons to offer to mitigate a murder. Heat of passion, and use of deadly force in defense of self or others when it wasn't justified by the degree of threat, are sometimes mitigating factors.

  1. Pride: includes honour killing, or murders to prevent being exposed or scandalized. Also includes murders motivated by hate
  2. Greed: includes robberies, erasing debts, contract killings.
  3. Lust: includes murdering a persons spouse so you can be with them, or crimes of passion. Also includes murders for sexual gratification, or caused by seeking sexual gratification
  4. Gluttony: excessive alcohol consumption or drug addiction is present in many murders. A drunk person can start an altercation or a drug addict can kill in an attempt to get money to satisfy their addiction
  5. wrath: heat of the moment altercation where someone goes too far, also includes revenge killing
  6. envy: includes jealous exes who kill either their ex or their exes lover
  7. sloth: includes deaths caused by callous indifference, and also more generally those caused by the depressive state of the murderer.

there is a reason after all they are called the seven "deadly" sins. just some food for thought.

The classic answer to this question is "love, lust, lucre, or loathing." It's said that any motive for murder falls into one of these four categories.

An unscientific list, in no particular order:
  • Domestic violence
  • Anger, obsession, hatred, jealousy, revenge, other transient emotions
  • Longer-term mental instability
  • Organized crimes, gangs, drug deals
  • Reckless or criminal behavior where somebody is killed unintentionally, treated as murder because of causal link
  • Mercy killings, vastly underreported
  • Eliminating a perceived rival, threat, hostile witness
  • Warfare, terrorism, insurrection (winers often declare the losers murderers)

Recreation, boredom, psychopathy, God complex, adrenaline, money, love, intense hatred, spectacle, eugenics, unwanted pregnancy, passion, jealousy, betrayal, sport, drug induced paranoia, population diminution, hunger, drug addiction, gang affiliation/initiation, revenge, retribution, state mandated execution, self loathing, copycat mission, wish fulfillment, convenience, evidence/witness tampering, example setting, displaced lust, necrophilia, necrophagia, embarrassment, humiliation, impotence, provocation...

I agree with the lists people have made and found this page particularly helpful too. There is a bit more written about all the motives Motives for Murder - Crimes Lab

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