Some of us are old enough to remember when there was no DHS. Many of the immigration-related functions fell under DOJ and even then there were issues sharing clearance data. Of course Secret Service was under Treasury, and they were legendary for not sharing clearance data. And now we have the Coast Guard in there as well.
I wonder if there are problems not only with transparency of DHS investigation and clearance data, but just with sharing clearance info among the various elements of DHS itself?