Maryland Code, Criminal Procedure § 4-102

(1) in a case involving a felony that does not involve a felony within the jurisdiction of the District Court, if the defendant is entitled to a preliminary hearing but does not request a hearing within 10 days after a court or court commissioner informs the defendant about the availability of a preliminary hearing; or

(2) in any other case, if a court in a preliminary hearing finds that there is probable cause to hold the defendant.