Jeremy Bamber is in prison because he would have inherited. Once his mam and dad were killed, there was nobody to protect him from Robert Boutflour and his daughter. His daughter had already labelled Jeremy as a 'threat' (to their livelihoods) prior to the killings. This is a very telling event (IMO) - as it clearly marks Jeremy's card. Some of Jeremy's own behaviour has simply reinforced the relatives' suspicion of him. The result being - anything that could be gleaned from events that pointed towards Sheila was dismissed. Everything that could be interpreted as pointing towards Jeremy was soaked up and fed upon in a kind of frenzy.
I believe much -if not, ALL- of what Ann has to say about Jeremy, to have been a parrot of what RWB said of him. I'm inclined to believe there was no little animosity on RWB's part, towards Nevill. It had been RWB who'd arranged for Nevill to work on the Speakman farm, but it seems that because of Nevill's financial position, he'd become far more affluent than RWB, to the point where it was he, rather than RWB who appeared to be the controlling force. Their positions, despite RWB being the elder AND married to the eldest sister, seem to have reversed. It's possible that RWB saw much of what the then childless, Bambers had accrued, as eventually finding its way to his side of the family. The advent of Sheila and Jeremy would have put paid to such notions. It's easy to imagine him grumbling/muttering, to Ann and David, about every penny the Bambers appeared to be 'wasting' on the adopted pair., when his two could have put it to much better use if it had been theirs............or his! I have no problem with this. It's how some families are. I'm very reliably told that it's how MOST wealthy families are. It's certainly how MANY families are when it comes to the inclusion of adopted children..........................but it doesn't mean that Jeremy is innocent.