OK alagator - I'll bite (pun intended)
If it is indeed wise to act BEFORE the crime is committed, then perhaps we should really get serious and treat everyone above the legal alcohol limit who gets behind the wheel of a car as if they are actually intending to kill a family. The punishment would have to be life in prison because we already know BEFORE the fact that they're going to kill a family as soon as they get out. This solution would certainly stop convicted DUI offenders from ever killing anyone. But what about first-time offenders - teenagers and the like? Maybe we should also hire geneticists to determine at birth who has the "alcoholic" gene and lock them up as soon as they reach legal driving age. That'd REALLY be effective in preventing the crime BEFORE it ever happens. Boy, what a wonderful country this would be then! But wait! Why stop there? We've cracked the human genetic code. There's all sorts of undesirables we could eliminate from society just by doing a little tweaking and genetic splicing. We could create a super race of people! Tut dieses Tonvertraute? This is not new approach. Just how far would you be willing to go down the slippery slope of convicting someone BEFORE an actual crime is committed?
Yes, Stabler should have known better. Yes, he deserves punishment for the crime he COMMITTED and not for the crime he COULD have committed. Someone (drunken or otherwise) who picks up a gun and "misses" another person, either accidentally or intentionally, should be punished for the crime they actually committed - not for Murder I. Taking away the offender's right to carry a firearm, for one, would make sense in such a case. Likewise, taking away a person convicted of a DUI's right to drive makes sense.
Giving a DUI offender and extended prison sentence when nobody is actually physically injured is just too harsh IMHO. But then again, my political center falls closer to Goldwater/Reagan conservatism with libertarian leanings than it does to many of the bloodthirsty, boorish, neocon proselytes out there who are always looking for a good hanging or witch hunt in order to feel themselves beyond reproach by comparison.
Stabler's reckless behavior as well as his contribution to society as a whole should all be taken into account. Put the pitchfork down and try not to ignore all the good he has done for charities and other humanitarian acts. After all, it's not as if the guy is some sort of a "snake".....OK, scratch that last comment. Maybe he's a snake. But he's also got a lot of fine human qualities. I'd rather reserve a prison cell for someone more deserving.