In a no-knock search warrant, can a search warrant be used to search a house without announcing its purpose?

Here, however, there was simply a knock and no announcement. While the 20 seconds or so that elapsed before the officers broke down the door was not unreasonable (see United States v. Banks, 540 US 31, 124 SCt 521, 157 LEd 2d 343 [2003]), there was no announcement of the officers' purpose in being there. It seems to this court that the failure to announce their purpose would rarely be justifiable when executing an arrest warrant. In executing a search warrant, the case is stronger for exigent circumstances; drugs can be flushed and records can be destroyed. Indeed, no-knock search warrants are frequently issued by this court for those reasons. An arrest warrant is executed only against an individual; it does not authorize a search of the premises except to search for the named person. In the instant case, there was no showing why the officers could not announce the reason for their presence when they knocked at the door. Thus, it initially appeared that the evidence seized for violating the knock-and-announce rule would have to be suppressed.