Those who "know" he's guilty believe that it HAS been resolved, way back in 1986!
What is unusual, is that JB is still protesting his innocence after 35 years. Most convicted murderers admit their guilt eventually.
Well he's managed to turn it in to a little cottage industry which has occupied him for decades.
And I think he continues to protest his innocence for a number of reasons, but one of the most compelling, in my opinion, is that there's mileage in the initial handling of the case and the fact that the evidence is circumstantial.
It's grasping at straws, but it also demonstrates that there's every chance that he's detached himself from the atrocity mentally, otherwise it would have consumed him by now. I also believe that this compartmentalisation started when he was stood outside the farmhouse with the police and saw the fruits of his labours come to fruition in ways he could only have hoped for - they initially bought his narrative wholesale. Now he doesn't 'think' he's an evil genius, he
is one (in his eyes). The ineptitude of the police reinforced his story to everyone including himself.