Md. Code, Crim. Law § 5-705

(a) Subject to subsection (c) of this section, in a criminal case involving counterfeiting of a prescription under this title, an affidavit by an authorized provider may be introduced as evidence that: (1) the signature on a prescription of the authorized provider has been counterfeited; (2) the individual named on the prescription was not a patient of the authorized provider; or (3) the individual named on the prescription did not have a prescription from the authorized provider for the named prescription drug or controlled dangerous substance or did not have a prescription for that quantity of the prescription drug or controlled dangerous substance. (b) The affidavit shall: (1) be attached to a copy of the prescription; (2) be given under oath subject to the penalty of perjury; (3) declare that the prescription is counterfeit or altered; (4) describe in detail the parts of the prescription that have been counterfeited; and (5) state whether a patient relationship exists between the individual named on the prescription and the authorized provider. (c) (1) At least 10 days before a proceeding in which the State intends to introduce into evidence an affidavit as provided under subsection (b) of this section, the State shall provide written notice to the defendant that the State intends to: (i) rely on the affidavit; and (ii) introduce the affidavit into evidence at the proceeding. (2) On written demand of a defendant filed at least 5 days before the proceeding described in subsection (a) of this section, the State shall require the presence of the affiant as a prosecution witness.