JM was the one obviously closer to JB so the more information that could be pumped out of JM, the better, whether true or not because a case had to be built against JB by the relatives as they knew nothing about the family dynamics etc.
The idea was to get as much information that would damage JB irreparably-----all without proof, that was used against him but said in such a way as to convict, and so it went on.
What was fair and just about this ?