Del. Code tit. 11, § 1903

A peace officer may search for a dangerous weapon any person whom the officer has stopped or detained to question as provided in § 1902 of this title, whenever the officer has reasonable ground to believe that the officer is in danger if the person possesses a dangerous weapon. If the officer finds a weapon, the officer may take and keep it until the completion of the questioning, when the officer shall either return it or arrest the person. The arrest may be for the illegal possession of the weapon.