Apparently the DCUSA security team abides by a "Stay in School" rule.
As I was walking into the complex around 2:45PM a security guard (or perhaps hired police officer, I am not sure) stopped two younger looking folks to quiz them about their ages. When it came out that they were school-going youth, he told them they couldn't enter the building until 3PM.
The kids left quietly and on the street I heard one say she got out early. Anyhow, the lesson: School is Cool, kids! Target is also cool, but only after 3PM.