Adam
I believe that a lot of things that were said about Jeremy during the trial were part of a "character assassination"
you have formed an image of him in your mind mostly from what Julie and a few members of the family said .
1) Do you think even if it was true , and a lot of posters have said they don't think he was a particularly
nice man - that being arrogant and possibly selfish ( although recall Barbara Wilsons first glowing statement

he was not that bad) Make you a murderer?
2) Experts are still arguing and giving different opinions on the blood in the silencer or if it was even used and argue about the DNA evidence
3) so take this out of the equation - and what did the police have to go on? No forensics. they could not prove ( see court transcripts) that he could lock the window from the outside. They could not prove how he had got back to the house . They could not prove any timings of calls because they apparently had dodgy time keeping. They had no times of deaths . They did not call in ballistic experts to examine the house .
They did not have a lot to go on - but the family were on and on at them and there would have been an inquest into the murders and suicide ( because lets face it that still would have been a crime) and a lot of their mistakes would have come out . So they could not really refuse to look at the other angle could they?
As for an absolute reason why?
Why have they done it in other cases ? Tbh I have not a clue .
Perhaps you should read the link I posted yesterday about officers resigning during investigations of corruption and MOJ , so they can keep their pensions. I am sure it is only a minority of officers but it does happen