When an officer is lawfully at someone's open doorway or a similar circumstance, it's my understanding that if he sees some kind of drug evidence giving him PC to request a search warrant from a judge, that he can then secure the house pending the warrant. How far does securing the house go? To ensure officer safety, can he look through closets and other places that a person may hide as long as he doesn't search those areas?
And what about the circumstance where an officer is outside and can see drug evidence through the window? Presumably, he puts that in the search warrant affidavit and secures the house while he waits for the warrant, right? But what if as he waits there, someone inside the house starts destroying that drug evidence? Does he have sufficient exigent circumstances to kick in the door or is he just SOL?

On the protective sweep isssue, the leading case is called BUIE. I don't have the cite here but officers can go pretty far in satisfying themselves the residence is free from threats to their safety.