Why the armed FBI raid on Stone? Maybe this.

[Toorich]

44. Plenty of Time to destroy evidence....

....and evident knowledge that he was a target.
But, like Michael Cohen, Manafort and others, I'm
betting he just couldn't get rid of the burner phones,
texts, emails and any other evidence that proves his
treason. They think they are untouchable.
These criminals have been running rampant since the
Nixon days.
Ford's pardon of Nixon.
Obama and Pelosi's refusal to consider war crimes prosecutions
for the Cheney/Bush cabal -"must look forward, not backward"-
The Bush I pardons of Iran/Contra henchmen Casper Weinberger and others
on eve of trial which covered-up Reagan's crimes.
Hell, they have been untouchable, and unless Trump is prosecuted and/or
convicted in an impeachment trial they will remain American oligarchs and
beyond the reach of justice.
"This is all ye know and all ye need to know."-Hunter S. Thompson