In the US those matters are taken very seriously. Those convicted usually get a stay in the Greybar Hotel. The exception was disgraced former general David Petraeus but, then again, his fall from grace (and prestige) was punishment aplenty.
Why April? Because the investigatory agencies, the State Department and the FBI, don't want to sabotage the DNC in this election year by leaving it any later.
Support for Hillary is already wobbly and waning and, with an indictment hanging over her head, many feel her campaign would be utterly derailed. If you're a Bernie supporter, don't count your chickens just yet. First, this is still only a rumour. Second, if Hillary is forced out that doesn't mean the DNC would back Sanders. There is an option and its name is Joe Biden.
I heard all about this through Ottawa backchannels recently. What I heard eerily mirrors a report from the Washington Examiner a couple of weeks ago.
The story I'm getting is that the Obama administration has been busy getting Biden back into circulation recently with a range of profile lifting activities from a tour of the Middle East to representing the White House at Nancy Reagan's funeral and a host of appearances in between.