Law & Order Search and Seizure question

This hearkens back to an old episode of Law & Order.

I don’t remember the specifics of the crime, but the police were in the process of obtaining a search warrant for the suspect’s apartment. The police who were going to perform the search were outside the apartment (suspect was not at home). The warrant had been signed by a judge, and was en route to the apartment, when the police at the scene received notification that the suspect was returning home. Since they didn’t want to give the suspect a chance to destroy evidence once he saw the police, one of the cops stuck a toothpick in the lock on the door. The suspect arrived, was unable to unlock the door, and was forced to wait outside fo rthe few moments it took for the warrant to arrive.

Later, in the, “Order,” part of the show, the judge threw out the evidence because of an illegal search & seizure.

So, my questions:
(1) Does the search warrant <i>have</i> to be on site for a search to be conducted, or does it merely have to be in the possession of the police? Particularly since the warrant was on the way, there was no attempt by the police to make the search “secret.” Must the warrant be shown to the homeowner prior to searching, i.e. what if he was not home when the warrant arrived? Would they have to wait for him to come home before the search was executed?

(2) If there was reasonable cause to issue the warrant, wouldn’t it follow that there was reasonable cause to detain the suspect (if even in the hallway) to prevent destruction of evidence?

Yes, yes, I realize it’s just a TV show, but I thought it was an interesting scenario. How much leeway do the police have in executing search warrants and at the same time preventing destruction of evidence?

Welcome to the boards, Lupus! Unfortunately, IANALOC, so I can’t help!