how to design a murder?

[satyesu]

i have the more structural details figured out - culprit, suspects, etc. - but how do i come up with a motive, method, etc?

[BigWords]

Motive. Easy question first.
Jealousy; revenge; money; sex; irrational hatred (perceived slight); hatred (real slight); to cover up a crime; in the heat of the moment; to see if they can get away with murder or just an accidental victim (the killer was trying to off someone else) or mistaken identity. There are others, and I'm sure someone else can point them out (I just listed my most likely approaches).

There are a number of cruel and unusual methods with which to kill someone, but I'm sure Agatha Christie has spoiled the well when it comes to wholly original ideas. Most methods fall into one of the following categories:
Poison; Gunshot; Vehicular homicide; bombs; radiation; stabbing; blunt force trauma; asphyxiation; electrocution; death by animal and... Other means. (Again, you'll get other suggestions from people who know more than I do).

The tricky part is hiding the obvious identity of the killer. That will only come when you have the setting, the deceased, the investigator and the surrounding characters working around the situation. The best murders are the ones that are obvious on second readings, but complete mysteries when you first read the book.

Every story is its' own thing, and a murder which works for one story will feel out of place in another. Once you start putting specific parts of the puzzle together it should all click in your mind - Like that feeling when you suddenly realise which blocks go where, and the Rubik's cube is done!

If any of that is a help? (I'm not sure where I was going with the Rubik's cube analogy)

[Soccer Mom]

I'm just puzzled as to how you have a culprit, but no motive. Those two work hand in hand. Why would culprit want victim dead? What would he benefit?

[Repartee]

I'm just puzzled as to how you have a culprit, but no motive. Those two work hand in hand. Why would culprit want victim dead? What would he benefit?

Exactly.

[BigWords]

I'm just puzzled as to how you have a culprit, but no motive. Those two work hand in hand. Why would culprit want victim dead? What would he benefit?

Oooohhh... I can think of one really good non-reason, and at least two rubbishy ways to get around the interconnection of killer and victim. It's a challenge to make the two characters co-exist but not co-exist (I call dibs on the absolutely zero connections / obvious when explained plot). *writing notes*

[Chase]

Motive for murder? Not capitalizing "I" when needed, using a hyphen in place of a dash, using random commas, ridding the world of people who watch America's Top Model or Bridezilla.

Motives are everywhere.

[Ruv Draba]

A suggestion: ignore the murder for a bit and write the culprit as a villain -- someone unlikable. Write about the villain's history, how the villain lives, what the villain wants.

Now introduce a change into the villain's life -- something that offers opportunity or threat. Something that the villain will kill to gain, to protect or to avenge.

Now put the situation and victim back into the frame and see what connects.

Do it that way and the murder will be so integral to the villain's personality that in retrospect it will be obvious that your villain dunnit. :)

[SirOtter]

Just a few random thoughts:

Each of your suspects must appear to be more or less equal in the sum of the three parts of murder: motive, method (access to and knowledge of the murder weapon) and means (opportunity to use the murder weapon). Suspect A may not have as strong a motive as the others, but his access to and ability to use the weapon may be better, while Suspect B might have the weakest alibi but no knowledge of the weapon used, and Suspect C might have the best motive and history of using the weapon, but an apparently iron-clad alibi, or a physical or psychological impairment that seems to preclude his being the culprit. Proving whodunnit based on motive alone is difficult, since motive is subjective. What might drive me to murderous rage might not even annoy someone else. Your detective will have to either break an alibi or prove more eptitude with the weapon than a suspect claims to have, or dig out some error in the execution of the crime somewhere that the murderer forgot to account for.

If your murder weapon is something anyone can get and use - a telephone cord, or a kitchen knife, or a fireplace poker, for example - skill won't much matter. Forensics will tell you more than anything else, unless the killer knows to remove his or her fingerprints and is a frequent enough visitor to the site that other traces left behind wouldn't necessarily point to him or her. If the weapon requires more specialized knowledge, however, you need for any seriously considered suspect to have at least a rudimentary knowledge of its use, or access to clear instructions.

Not sure if I answered the question, but maybe there's something in there that you can use.

[Cassiopeia]

I'm just puzzled as to how you have a culprit, but no motive. Those two work hand in hand. Why would culprit want victim dead? What would he benefit?I tend to agree with you on this. I don't see how you can have the criminal without the crime and without the crime...there's no motive...and wow...my head hurts.