Earlier, I wrote at length about this, but here's a little more.
According to David Cunningham:
While the F.B.I.'s campaign against antiwar ''subversives'' was largely ineffective, a considerably less ardent campaign against the Ku Klux Klan and its allies proved devastating. In the late 60's and early 70's, membership in white hate groups dropped as much as 70 percent.
in a number of other cases in the 1960s, Klansmen succeeded in harassing, infiltrating or tampering with jurors. FBI documents suggest that's what happened in 1968 when a jury deadlocked 11-1 in favor of the guilt of Bowers, who avoided a conviction then for Dahmer's killing.
My last quote is from an article by Jerry Mitchell on a possible new case against one, but not all, of the parties responsible for the murders of Michael Schwerner, Andrew Goodman, and James Chaney.
COINTELPRO was not so devastating as to stop the Klan from obstructing justice in murder cases.
Same point as before: When it comes to the Klan, the FBI has been a miserable failure at law enforcement.