Things I don't understand

Prof wanted in killings found dead in Ga. woods
By KATE BRUMBACK, Associated Press
9 May 2009
ATHENS, Ga. – Cadaver dogs found the body of a wanted professor "beneath the earth" in the north Georgia woods Saturday, two weeks after police say he shot his wife and two other people to death outside a community theater, then vanished.
[emphasis added]

Okay - your life isn't going according to plan.
You've lost your job, your kids are drug addicts, your wife is cheating on you.
You're a failure.

Why murder-suicide?
Why not simply suicide?
Yeah - you screwed up... fine: kill yourself.
Why kill your kids? Your wife? Your friends? By-standers???

If you want to kill the kids, the wife, friends, by-standers - okay...
... BUT: if that's your plan, DON'T kill yourself afterwards!!!
Face the music.

If you just want out of the hopeless situation - go ahead, kill yourself...
... BUT: don't take the wife & kids with you - they still have lives to live.

Again, this is under the rubric, "Things I don't understand."