Md. Code, Criminal Law § 9–301

(a) In this subtitle the following words have the meanings indicated.

(b) “Official proceeding” includes a criminal trial, a hearing related to a criminal trial or adjudicatory hearing, a grand jury proceeding, and any other proceeding that is part of a criminal action or juvenile delinquency case.

(c) “Victim” means a person against whom a crime or delinquent act has been committed or attempted.

(d) “Witness” means a person who:

(1) has knowledge of the existence of facts relating to a crime or delinquent act;

(2) makes a declaration under oath that is received as evidence for any purpose;

(3) has reported a crime or delinquent act to a law enforcement officer, prosecutor, intake officer, correctional officer, or judicial officer; or

(4) has been served with a subpoena issued under the authority of a court of this State, any other state, or the United States.