IIRC the FBI found out about the cash after Hurricane Katrina when he had the National Guard put their rescue activities on hold to go get his freezer with the cash.
IIRC, the cash was in the freezer of his home near Washington, D.C., not at his residence in LA. He did get the NG to make accomodations to get his to his house in LA, but that was probably because of another stash.