Executive summary: the Inspector General for the Department of Justice did an independent - no, let's be honest; it was an "internal" - investigation into the horrifically botched multi-agency program known as Operation Fast & Furious (OF&F). For those who don't remember, OF&F was that program where we let Mexican drug gangs illegally buy guns, didn't keep track of the guns, and pretty much watched as said gangs shot up Mexico. This all eventually led to the death of an American Border Agent Brian Terry; the stink from that caused all sorts of investigation, including one from Congress; and this... report... from the IG.
It's a 512 page document, but here's the meat of it: the Justice Department threw at least deputy assistant attorney general for the Criminal Division Jason Weinstein to the wolves, the better to keep his superiors safe. You see, the report solemnly concludes that Eric Holder didn't know a darn thing on the subject before early 2011... despite the fact that the report itself admits that virtually everybody else did, much earlier (a handy reference guide to timeline and players can be found here and here). House Oversight Chair Darrell Issa isn't particularly buying this; I'm sure that his response will be memorable.
More as I digest it: I suspect that Jason Weinstein isn't going to be the only sacrificial victim, here.