When you are that age, a few months passes like a few years. Young adults don't do well forecasting into the future. They just don't. Time only speeds up the older you get. Ultimately, my guess is they felt trapped and all they could see was the overwhelming repeated pattern over and over. Especially, if they had kids and family around them lived the similar lifestyle of brushes with the law, time spent in, etc. They most likely wanted a fresh start and better life.
I agree with this. Though released a couple years later, Rod Stewarts son-Young Turks, sums up the feelings a lot young people trapped in small towns just digging bigger holes for themselves felt. It's a bad cycle.
"But there ain't no point in talking when there's nobody listening, so we just ran away".
They seem to have their own page now.
https://en.wikipedia.org/wiki/Murder_of_Jimmy_Hendricks_and_Kim_Mills