This law requires that a notary use personal knowledge to ID the signer or that a credible witness be used to identify the signer.
(3) A notary public in this state may perform acknowledgments or verifications on oath or affirmation by means of a real-time, two-way audio-video communication, according to the rules and standards established by the secretary of state, if:
(a) the signer is personally known to the notary or identified by a credible witness and, except for a transaction described in subsection (3)(b)(iv), is a legal resident of this state; and
(b) the transaction:
(i) involves real property located in this state;
(ii) involves personal property titled in this state;
(iii) is under the jurisdiction of any court in this state; or
(iv) is pursuant to a proxy marriage under 40-1-213 or 40-1-301.
http://leg.mt.gov/bills/2015/sb0399/SB0306_x.pdf (See page 14)