Most people assume that the FBI is shrouded in secrecy, but they actually leave a lot out in the open. They choose to be super transparent on most things so that the things that are classified can be respected. These are some things that the FBI is open about, including how to be an agent and who gets to break some rules.
All Forensics Evidence Goes To One Lab
It may seem like it would make the most sense for the FBI to have multiple forensics labs, but it's actually quite the opposite. The department has one lab that they push evidence through. This is to make sure that there is little room for error; the less the evidence is floating around, the more likely results will be accurate.