Why couldn't they have instead just ran away? Maybe it was more than a desire to live happily ever after. Maybe it was revenge.
Perhaps, but revenge for what?
A teenage girl in ID blew her mom and dad away with a hunting rifle a couple of years back.
Why? Because her father had not only forbidden her to continue to see her much-older illegal immigrant boyfriend, he had dragged her from her boyfriend's bed and out to the family car in front of the neighbors and she was "humiliated."
So, as revenge for the humiliation, she put a 30.06 round in her mom's face while she slept and then put three rounds into her father as he ran out of the shower to see what the commotion was.
Because they had embarrassed her.
It does sound like revenge. Reminiscent of Charlie Starkweather and his girlfriend in the 1950s. They srarted their murder spree by killing the girl’s family.