I used to work with a Border Patrol agent whose duties included watching for criminal deportees returning to the area. As soon as he would get a tip on somebody he would immediately go to the DMV (Washington State) because these people had little to fear from the state. Their first stop after coming back was to get a new license. That would get us a current picture, but the addresses were always fake.
Hit the insurance agents and carriers in this country up. They have the addresses to the illegal aliens in their databases. Hit every landscaper, every painting company, every contractor, and every subcontractor. You would find half of the 50 million illegal aliens in this country, this way.