General Discussion

It’s logged when collected, logged when transferred from one person to another. Logged when put in storage. Logged when removed or searched or viewed. Evidence tracking tools would have to have been altered and all that is logged separately if it’s computerized. All the people that provided evidence or testimony or depositions also know what their involvement was.
Covering all this up has to be a massive operation in itself.
I hope some agents still have scruples and are keeping evidence of the cover up , if not some of the original evidence to blow it all wide open eventually.
Spoliation of evidence is a serious crime in itself.