Life is cheap to some people. Murders have happened over billions of dollars, and over issues as trifling as "he looked at me wrong." Murders have happened with no motive at all, simply because Life Is Cheap to some people. There isn't necessarily a motive, and if there is (and we ever find out), it's not necessarily anything that is going to make sense to us. We're all here because we think that every life is precious, that every life counts. But if life wasn't cheap to some people, there would be no need for a Websleuths. Arguing that this crime would or would never happen over a small amount of marijuana, or because someone would or would not kill children over a small amount of money, or drugs, or because the moon was full or whatever, ignores the fact that murders happen all the time, to victims of all ages, simply because life is cheap to some people. There's no "code of conduct" for criminals, no minimum $ limit or ethical boundary or internal logic that applies across the board. You can't really use "the mindset of reasonable people who are interested in justice to the point that they frequent Websleuths" as the standard for what a criminal would or wouldn't do or think. Of course it doesn't make sense to us that someone might kill a family for a small amount of money, or a small amount of drugs--because none of us would ever think of doing such a thing. When the motive does become public, whatever it is, it will seem small, and petty, and incomprehensible to us, because we're not people who would ever deliberately kill someone for any reason short of self-defense.
Now, I'm not saying that this crime had anything to do with any amount of money or drugs; I haven't been following this case particularly closely, and I don't have any particular opinion. But it does drive me crazy when people say, "Oh, no one would kill a whole family over something like that," or "no one is getting murdered over small amounts of pot/alcohol/jealousy/a new pair of shoes/such a small life insurance policy/because the murderer was having a bad hair day*, etc." Because people of all ages are killed all the time any number of reasons that are incomprehensible to reasonable people. For others, the lives of four people are, in fact, worth less than a dime bag of pot. That very well may not be the case here--but it's the case to someone, somewhere. That's the reason it's often most productive to talk in terms of statistical probabilities rather than absolutes.
Confession: I do sometimes feel murderous over a particularly bad hair day.
