I applied on the USA jobs site. After waiting a few months, I was contacted by the head of the intern department. She emailed me saying that I had been accepted. After I accepted the offer, I went to the DC branch to check in and for security clearance. After being cleared, I talked to her about when I could start. She was very prompt in responding emails and answering any questions I might have had. It was a very quick and easy process. There was no interview.