The "conviction rate" at the federal level is basically a BS statistic because it includes plea bargains and federal prosecutors have a much greater degree of choice when it comes to pursuing prosecution compared to state and local prosecutors. Most of the convictions are drug an immigration cases (29% and 21% respectively in a recent example year) and if you were to look at the actual conviction rate of cases where the conviction comes from an actual court verdict the rate is much lower. An odd little factoid here is that for cases that go before a jury the conviction rate is in the low 80% range while bench trials before a judge have a conviction rate in the mid to high 50s.
Which is exactly why the crimes are so loosely defined. The prosecutor loads up a defendant with every conceivable charge, in the expectation that they'll plead guilty to avoid an absurdly long sentence. Only the bravest, most foolish, or truly innocent will risk a jury trial. Plea bargaining is illegal in some countries for this reason.
