The NYU Journal of Law & Liberty is hosting an online symposium tomorrow about anticipatory warrants and the Fourth Amendment, a hot topic these days in light of the pending U.S. Supreme Court case United States v. Grubbs. Participants in the symposium include James Adams, Brooks Holland, Andrew Leipold, Chris Slobogin, and myself.

  The Journal has just posted our introductory comments. Tomorrow, we will be blogging responses and additional comments throughout the day.

  Here is my introductory comment:

  One of the most specific commands in the Bill of Rights is the Fourth Amendment's prohibition against issuing warrants without probable cause: "no Warrants shall issue, but upon probable cause, supported by Oath or affirmation, and particularly describing the place to be searched, and the persons or things to be seized."
  Over two hundred years after the Fourth Amendment was enacted, this prohibition still means what it says. Before a judge can issue a warrant, the warrant must be based on probable cause; must be supported by oath or affirmation; and must contain a particular description of the place to be searched and person or things to be seized.
  Anticipatory warrants are warrants that are issued when probable cause is anticipated but does not yet exist. The idea is that some future event may happen, and when it happens, probable cause likely will then exist. (I say "likely" because the magistrate judge never knows what else will happen in the future just before the event occurs. He will normally assume that nothing else of importance to the case happens before the future event occurs, but of course cannot know that with certainty.) The officers executing the warrant can wait for the event to happen, and then execute the warrant. If all goes as planned, probable cause will exist when the warrant is executed, even if it didn't exist when the warrant was issued.
  If we approach anticipatory warrants from the standpoint of normative policymaking, there are considerable arguments for and against anticipatory warrants. But for my introductory comment, I want to focus our attention on the Constitutional text. Am I missing something, or does the text of the Fourth Amendment answer this question for us? The text says that no warrants shall issue, but upon probable cause. In this context, it seems to me that "upon" means "following the establishment of" and "issue" means "signed by the judge." If that's right, doesn't the plain text of the Fourth Amendment prohibit anticipatory warrants?

  More tomorrow over at the NYU Journal of Law & Liberty.