What DNA evidence did EP destroy, a decade later that would have benefitted Bamber ?
The silencer was tested for DNA & found June's.
The bedclothes & carpets were destroyed in 1985. The bodies were not available.
Off the top of my head, all of the bloodstained pyjamas, bullet casings and ballistic evidence plus bloodstained carpet and bed sheet samples were destroyed. Whilst it is true that the bedclothes and carpets were destroyed days after the killings, this was after samples were taken. This is well documented. The silencer is the only forensic exhibit not destroyed. There is much more but these alone could establish who committed the killings.
The blood and DNA of the victims would be all over Sheila's clothes, if she were the killer. Neville's pyjamas could have been tested for DNA to establish who he was struggling with, Jeremy or Sheila?
It is beyond dispute that these items were destroyed, contrary to court orders and is well documented. DNA testing would have established the truth or otherwise of the prosecution case but EP and Special Branch were apparently keen to prevent this.