It appears that a lot has been going on in the background of this case for the last few years. The bootlace that had been "tested to destruction" has now been found and Stone's solicitors have been pushing for it to be tested against Bellfield's DNA.
https://www.bbc.co.uk/news/uk-england-kent-57055719 The Met are also investigating him over unsolved bludgeon cases dating back to 1990.
I don't think that it is guilty conscience, empathy with Stone over some hatred for women or not receiving "credit" for his crimes that have led to the latest developments as has been suggested. He appears to be more worried that he is about to receive the "credit" for his unaccredited crime spree.
There is obviously a lot of pressure being applied.
The recent developments make it all the more baffling that Kent Police are still refusing to investigate, or perhaps make it clear why Kent Police are not re-investigating. Depends on your level of cynicism.
As Nugs succinctly pointed out earlier, Milly Dowler, would still be alive if Kent Police had done their job properly. Amelie Delagrange who he murdered in 2004 and Marsha McDonnell who he killed in 2003 would still be alive.
There is also the attempted murder of Kate Sheedy in 2004.
The jury failed to reach verdicts on further charges of abduction and false imprisonment of Anna-Maria Rennie in 2001 and the attempted murder of Irma Dragoshi in 2003.
It makes the already weak argument, ie. locking up a dangerous individual (Stone) for something he didn't do because he is dangerous anyway, look as unethical and as stupid as it is.
By any measure Bellfield is a way more dangerous individual than Stone, by magnitudes.
Is this the reason that Kent Police are unwilling to investigate the new evidence. All of those known and probably more unknown victims of Bellfield after the time that Kent Police should already have apprehended him.
There is the also not small matter that Stone would be due a huge pay-out for his wrongful conviction. His conviction would not only be overturned but somebody else (Bellfield) would be convicted. The rules regarding compensation for overturned convictions mean that compensation is not usually paid but I believe that would not be so in this case if Bellfield is ultimately convicted.
It seems that the shit is moving rapidly towards the fan.