It didn’t violate the Fourth Amendment for a state issued GPS warrant in Michigan to track a car into Indiana. Territoriality is a state law issue, hardly ever a Fourth Amendment issue. “The problem with Castetter’s principal argument is that the Fourth Amendment does not concern state borders.” United States v. Castetter, 2017 U.S. App. LEXIS 14362 (7th Cir. Aug. 4, 2017):
Prosecuted under federal law, 21 U.S.C. §841(a)(1), Castetter moved to suppress the evidence found when the police executed the second warrant. He did not dispute the validity of the first warrant or the existence of probable cause to support the second warrant, but he contended that information derived from the first warrant should be ignored—and, if it is ignored, the second warrant would lose its foundation. Castetter observed that Holst lives in Michigan, where the first warrant issued, while he lives just across the border in Indiana. As Castetter saw things, Michigan’s police lack authority to monitor the location of a car in Indiana, no matter what the Michigan warrant says. Castetter’s fallback argument is that the first warrant pertains to Holst, not him, and that police (whether from Michigan or Indiana) were forbidden to learn who was doing business on his property without obtaining a warrant based on his own activities. The district court rejected these arguments and denied the motion. 115 F. Supp. 3d 968 (N.D. Ind. 2015). Castetter then entered a conditional plea of guilty, reserving the right to raise the suppression argument on appeal, and was sentenced to 108 months’ imprisonment.
The problem with Castetter’s principal argument is that the Fourth Amendment does not concern state borders. It reads: “The right of the people to be secure in their persons, houses, papers, and effects, against unreasonable searches and seizures, shall not be violated; and 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.” Nothing there about state lines. The Constitution demands that a warrant be supported by probable cause, an oath, and particularity. As we have already mentioned Castetter does not deny that these requirements were satisfied.
States may decide as a matter of domestic law not to authorize their police to acquire information extraterritorially, but federal courts do not use the exclusionary rule to enforce state-law doctrines. See Virginia v. Moore, 553 U.S. 164, 128 S. Ct. 1598, 170 L. Ed. 2d 559 (2008). States also may elect to ignore information given to them, by other states’ officers, about what happens within their territory. As far as the Fourth Amendment is concerned, the Indiana judge who was asked to issue the second warrant could have said: “I don’t think that the Michigan police have any business insinuating their GPS locators into this state, so I refuse to issue a warrant.” But the Indiana judge did not say that. So we have not only the principle of Moore that violations of state law do not justify suppression in federal prosecutions, but also the (implicit) decision of the Indiana judge that there was no problem, as a matter of Indiana’s law, in using information about Indiana sent to police in Michigan.