A person aggrieved by an unlawful search and seizure may move the district court for the district in which the property was seized or the district court having jurisdiction of the substantive offense for the return of the property and to suppress the use, as evidence, of anything so obtained on the ground that (1) the property was illegally seized, or (2) the property was illegally seized without warrant, or (3) the warrant is insufficient on its face, or (4) the property seized is not that described in the warrant, or (5) there was not probable cause for believing the existence of the grounds on which the warrant was issued, or (6) the warrant was illegally executed, or (7) the warrant was improvidently issued. The judge shall receive evidence on any issue of fact necessary to the decision of the motion. If the motion is granted the property shall be restored unless otherwise subject to lawful detention, and it shall not be admissible in evidence at any hearing or trial. The motion to suppress evidence may also be made in the district where the trial is to be had. The motion shall be made before trial or hearing unless opportunity therefor did not exist or the defendant was not aware of the grounds for the motion, but the court in its discretion may entertain the motion at the trial or hearing.