Let's make it simple: Anyone without an in-date visa has 10 days to report to a detention facility for outprocessing, or they will be shot. Anyone from Iraq, Egypt, Saudi Arabia, Algeria, Jordan, Syria, Pakistan or Afghanistan with an in-date visa has fifteen days to report for screening (significant numbers of legal visa holders from these countries are enemies of their governments). Any permanent residents from the above places will be given thirty days to report for screening.
All aliens must register with local police every 1 January, every year.
As an interesting side note, I heard on fox news today that 13 of these terrorists had Social Security numbers.