been concerned about all week the concern of the holiday, and corresponding with ramadan, so i certainly think all of that contributed to today's response but at the same time there has been a history there at the navy yard in that building from the shooting there a couple years ago, so i'm sure that also played a role. >> thank you pamela. federal authorities have put out a nationwide alert, has already been stepped up for the holiday. let's bring in our justice reporter evan perez. you were among the first on the scene at the navy yard. people were frightened. >> it was visible. there were people shaking, women hugging each other. this was a traumatic event for them and there were people i talked to who came out building 197, which is the building where a shooter stalked the has, and shooting them so the fear was very real very palpable.