IIRC, the Sheriff said to forget the BC. So they must have found something else. The mothers passport shows he lost citizenship. What they may find is a statement by Barak, that he became a citizen around 1970. He may have documented it when applying for a drivers license or passport. There may be a record of immigration of a boy named Soebarkah, from 1970. He may have arrived with an Indonesian passport. These things get recorded in multiple databases and paper.
Perhaps I’m late to the discussion, but does this explain why the Obama administration has denied Joe access to the DHS databases? Is this because the Illegal Immigrant in Chief doesn’t want Sheriff Joe to investigate his immigration papers?