Is a sworn statement valid if it is not signed by witness and person conducting oath does not sign?

I would contact your local JAG, Area Defense Counsel (ADC), or a local attorney for that answer. I would say, under certain circumstances, any written (as in personally wrote by hand using pen and paper, not electronic) MAY be considered an official statement.

As a Public Notary for the State of TN, generally a statement isn't considered "official" unless signed and witnessed in a notary's presence and then have the notary affix their seal and signature. Statements taken by law enforcement during the course of questioning in regards to suspected criminal activity fall under different rules. That will definitely require consultation with an attorney.

As always, seek IG and JAG. Those would be your best resources for legal questions. Let us know what you find out.

I am currently going through the same situation, I would like to know how your article turned out and what information did you receive from legal.