As I suggested in the opening brief, that's 90% of the work in building the case file, insofar as we are focused on high- and highest-level perpetrators. With the Syrian regime's military, political, and security intelligence structures, establishing the linkages between the highest levels of the regime and the physical authors, if you will, of the underlying acts is relatively straightforward. That's what informs our heavy emphasis on securing regime documentation and moving it westward.
It's much more complicated with Islamic State—and I'm choosing my words carefully here, because we're not in camera. Effectively, with Islamic State we do secure documentation, but we are much more reliant on other forms of information that are more difficult to turn into admissible evidence. I speak to sensitive sources inside Islamic State structures. There are enormous volumes of material that we have secured, and do secure, through cyber-exploitation processes—captured computers, telephones, hard drives, and so forth. Other forms of open-source material are generated by IS itself via the social media revolution. I'm too old for this, but it's YouTube, Instagram, Telegram, Facebook, and these sorts of things.
The difficulty is not building the linkage case; ultimately, and here I speak to Islamic State, it will be transforming it into admissible evidence at trial. One of our national partners has a great deal of experience doing terrorist prosecutions over a prolonged period, and they have been advising us on some of the challenges and solutions to these problems.