An anticipatory search warrant is what is used when prosecutors have concrete proof that a crime will happen in the future. Anticipatory warrants are also used when police intercept contraband. These include: drugs in the mail, child pornography in the mail, captured military weapons, and information on fugitive locations.
The most common example of an anticipatory search warrant is when police intercept drugs in the U.S. mail. Typically, a canine alerts a package. Then the package is examined and drugs are discovered. There is always a fake address or no return address at all. From the standpoint of the police, the only concrete investigative lead is the destination address. The officers, at this point, draft an anticipatory search warrant, asking the judge for permission to search the home where the package will be delivered even though the package hasn’t actually been delivered yet.
In United States v. Grubbs, 547 U.S. 90 (2006), the Supreme Court of the United States decided on the constitutionality of anticipatory search warrants under the Fourth Amendment to the United States Constitution. The Court ruled that such warrants, which are issued in advance of a “triggering condition,” are executable and constitutional.
The biggest difference between a normal search warrant and an anticipatory search warrant is the requirement of what is known as a triggering condition. When police officers get an anticipatory search warrant from a judge, the warrant is based on probable cause that, at some future time – but not now – evidence of a crime will be at a specific location. The Fourth Amendment doesn’t define “probable cause.” An affidavit has to establish beyond a suspicion that criminal activity is likely, but does not have to prove it beyond a reasonable doubt.