I don’t think they have to power to grant immunity from prosecution. Only the AG can do that.
But they could have put the AG between a rock and a hard place and forced her hand.
Washington can leak like a sieve sometimes.
2 points, ( 1 ) the Fbi has had the hard drives now over 10 months,yes,even what Hillary deleted and ( 2 )
There are many elected congree ans senate names guilty too
That was the Fbi leverage