Wonder why no one's mentioned Charles Starkweather and Caril Fugate's little romp in Nebraska and Wyoming in 1958?
It sounds exactly like the same thing, only they caught this murderous SOB before he could go on a killing spree like Starkweather did (killed 11, I think).
It's been mentioned on several of the threads. It's one of the first things that came to my mind, too--that shows my age, doesn't it?