It is still not publicly known who first told the columnist Robert D. Novak the identity of the C.I.A. officer, Valerie Wilson. Mr. Novak identified her in a column on July 14, 2003, using her maiden name, Valerie Plame. Mr. Fitzgerald knows the identity of this source, a person who is not believed to work at the White House, the lawyers said.
Unclear what "not believed to work at the White House" means - does this exclude former employees?