concurring.
I concur in the remand in this form because it provides a self-executing mechanism in the event the District Court finds, on the entire record, that § 3109 was not violated. It should be clear that while time lapse between the police announcement and a break-in cannot be rigidly defined, the law plainly requires that police identify themselves as such and that they state their warrant authority before breaking in. Inevitably an accused found with incriminating materials will deny police assertions of compliance with the statute. The conflict in testimony must then be resolved by the fact trier. Appellate review of such findings is narrow and limited but they are reviewable.