The phone interview was very easy and no preparation is required.
The in person interviews are set up at the Booz Allen headquarters in Virginia and take about 2.5 hours. A recruiter meets with you first to lay out who will interview you and to review your application. Three Booz Allen employees then interview you, each focusing on a different aspect of your background such as functional knowledge or leadership. They ask you repeatedly to tell them about a time when you used your skills.