JB can't be blamed for coercive/controlled behaviour towards JM as he was too busy flitting about from one woman to another so was never the " steady boyfriend ". It was when Sheila had moved to London that JB was beginning to feel his feet and the grass was looking a lot greener there than in the insular environment of where he was.
He'd obviously enjoyed the party atmosphere that was London and probably what went on in his mind was the continuing boredom of a relationship that was going stale.
Because of the more or less sheltered lives that both he and Sheila had led at WHF the thought of them both spreading their wings felt like a different way of life altogether which both enjoyed.
During this new found life, it was JB who'd looked after his sister, driving her home from clubs/parties. I don't know many brothers who'd look out for their sisters in this way while enjoying themselves ?
A psychopath would just let them get on with it----being void of any feelings etc and would continue to do what they wanted as is a psychopath's nature, selfish and uncaring.
We don't know the enjoyment that JB had while JM was out of sight ! if JB had had eyes for JM I'm almost certain that he would have got engaged to her, but he wasn't interested and apart from the fact that June never got on with her that relationship was fizzling out before the murders ever took place and JB was looking for a way out.
His chance came when he got that phone-call while JM was in his presence and that pretty well marked the end of the relationship.
At 24 it's not a hanging offence to end a relationship. If JB was as bad as he's been painted why was JM hanging on to him for grim death ? Why was she so furious with him and wanting to suffocate him ?
Girls/young women are renowned for throwing all kinds of " tantrums " and acts of revenge after a split, you read about these things every day and this is exactly what JM did during her stand as a prosecution witness-----which she did very well until it came to her being questioned about the man she'd once loved and she couldn't speak through the tears after realising what she'd done !
This is well-written lookout but inaccurate. It's true Jeremy was the one with the car and Sheila couldn't drive, and maybe he did take her home on occasions when his judgement wasn't affected by cannabis or alcohol. But after her illness in 1983 I think he began to see his sister as a liability, someone whom he didn't want to be seen with at parties, and whom he began to pity. Remember in his mind these were mercy killings, as well as justifying to himself that Colin would be able to obtain full-time work once the twins were out of the way. These thought processes really are the product of a diseased mind.
As for Julie, why did she stick with him for so long, listening to his insane rantings on the subject of killing five people, by his side at the funerals, and as you say only when it was clear Jeremy was going to date other women did she snap? Did she think she was entitled to some reward for her silence, did she turn down the offer of manageress of a wine bar in a fashionable area of town, why had she not become pregnant by him if she really wanted to hook him or was otherwise purely interested in the material aspect of their relationship?
I think that she did love him, she was a martyr to his every wish, she was available for him at all times sexually, she did his washing, decorated Bourtree Cottage. She wanted desperately to believe he wasn't behind the murders, that somehow Matthew had misunderstood instructions, that it was all a ghastly mistake, until she saw the carcasses themselves laid out on the slab and the curtain descended, until the admission at Blazer's restaurant, Blackheath that there was something wrong with him, that she realized she had to get away from Bourtree Cottage and its associations, that after the murders there really was no future for them, because powerful an emotion as love is, it just wasn't enough..
