Legal Question in Employment Law in Virginia

Yes, of course, you can sue such an employee for defamation but it is important

to distinguish whether the alleged defamation was committed within the scope of this employee's employment and whether as a federal employee he may have a defense to the charge known as qualified immunity.

And, yes, there would undoubtedly be a statute of limitations applicable to

the matter, which would probably be the Virginia statute which I believe is one year.