(1) The defendant may waive a preliminary hearing.

(2) If the defendant does not waive the preliminary hearing, such hearing shall be held within a reasonable time but no later than 10 days following the initial appearance if the defendant is in custody and no later than 20 days if the defendant is not in custody, provided, however, that the preliminary hearing shall not be held if the defendant is indicted before the date set for the hearing. In the event the preliminary hearing is not held within the above time period, the defendant shall be discharged from custody, and he or she shall thereafter be proceeded against on that charge by indictment only. Unless the defendant consents to an extension, time limits may be extended by the court only upon a showing that extraordinary circumstances exist and that delay is indispensable to the interests of justice.

(3) Notwithstanding waiver of the preliminary hearing, at any time before the defendant has been indicted the attorney for the Commonwealth shall, upon demand, be entitled to a preliminary hearing for the purpose of examining witnesses. The defendant may cross-examine the witnesses offered by the Commonwealth.