Then why wait a week before the election?If it's something big enough to get her arrested immediately they should release it now. Anything else would take too long through the system that she couldn't even be charged until after the election, just due to investigation necessary given the source and circumstances of the release.
But you release that close and there is no way in hell it isn't fresh in the minds of voters when they go into the polls, plus Clinton ends up spending all that time responding to that charge as opposed to simply campaigning normally or effectively attacking Trump. Which, if your goal is making sure Clinton doesn't get the presidency is a pretty good strategy.
Pound for pound, the amoeba is the most vicious animal on earth.