Well what evidence convinces you JB is guilty? I have looked hard and am struggling, there is serious doubt at everything I look at?
Bullet points will do, lets see what you can come up with you seem very sure the conviction is safe.
He was given away by Juliet at six weeks old. He never truly bonded with his adoptive parents and was again sent away at eight years old. Possibly looking for affection and companionship amongst the pupils of the landed gentry of East Anglia he let slip that his birth parents weren't married when he was born and came to be labelled "The Bastard." He felt intimidated and apprehensive throughout his schooldays, gaining a modicum of acclaim through his shooting prowess.
He left Gresham's with few academic qualifications and enrolled at Chelmsford College, where the less stuffy atmosphere was more to his liking. Yet he still achieved very little, opting to travel to Australia and New Zealand in July 1980 instead of settling down to working life at White House Farm.
Upon returning to England in 1981 he got a job at Little Chef off the A12, enabling him to circumvent his parents' supervision yet again. Around this time he began a relationship with Suzette Ford, whom he met at the Frog and Beans in Colchester, the centre of his social life. She was separated from her husband and already had three children. Jeremy wished to marry her, but upon discovering the relationship June banished him from the Farm and disinheritance was discussed. Suzette suffered a miscarriage, which may have left an ineradicable imprint on Jeremy's mind. Yet again another chance to avoid this diabolical tragedy was lost, when Suzette returned to her husband.
With Jeremy's resentment of his parents' influence growing he demanded and received a loan of several thousand pounds from Nevill for a second trip to the Antipodes, arriving in New Zealand on 2nd August 1982. This is when his plan to become a scuba diving instructor came to nothing when he failed a medical, possibly as a result of June dropping him on the head when he was a baby. He struck up a relationship with Brett Collins, who fancied himself as an expert in antiques. One has to wonder whether the murder plans were incipient at this stage, Jeremy filing Brett's name in his head as someone who could be useful to him in the future.
With his mother's breakdown occurring the same year and Sheila's the year after Jeremy seemed to grow in confidence, especially as Nevill seemed downcast due to his wife and daughter's illnesses. He began to take an interest in the farm, probably connected with the conditions of his father's will, which he had secretly perused after purloining the safe key. Two statements may explain his mindset at this juncture: when asked by Julie why he didn't just clear out he replied: "because I've got too much to lose.". When farm secretary Barbara Wilson was asked about Jeremy's new-found enthusiasm for farming she remarked that Jeremy rarely did anything without an ulterior motive.
We know that Jeremy considered several methods of killing: the prescription tablets of Julie's, the burning of the Farm he speculated to Malcolm Waters at Christmas 1984, and of course his sounding out Julie, probably the first intelligent woman in his life who took the trouble to listen to him.
The final straw might have been Sheila's second illness in March 1985 and the drain on the Bamber finances from a source who was always unlikely to earn her own income. The effusive way his parents treated the twins, in contrast to the unexpressive way he had been reared, and the fear that they too would be sent away to public school for ten years at the Bambers' expense may well have been a factor. His quizzing of Colin as to the dates they were to stay at the Farm is another giveaway.
All had to be under the one roof for his plan to work, and all had to die.