In Baton Rouge, the secretary of state’s office is very diligent and removes all who die from the rolls usually before they are interred, certainly within a few days. They must comb the obituaries of the major papers each day. They don’t wait for a certified death certificate to reach that office.
The Lousisiana Code regarding Death/removal from voter roles. I don’t see
why this approach can’t be used nationwide as it seems simple enough.
http://legis.la.gov/lss/lss.asp?doc=81499