In State v. Estrella, No. 2 CA-CR 2011-0076 (Ariz. Ct. App 2012), the Arizona Court of Appeals held that the use of a GPS device on a vehicle without a warrant does not violate an individual's reasonable expectation of privacy.
The defendant was convicted of multiple drug crimes, and on appeal, he argued that the convictions should be reversed because of the warrantless use of a GPS device on a vehicle driven by him. The van was owned by his employer, and the device was placed on it while in a public parking lot. His motion to suppress at trial was denied.
However, the defendant had not made an argument under Jones' trespass theory at trial, but instead under a reasonable expectation of privacy argument. As such, the court reviewed the trespass theory only for fundamental error and considered it waived.
The appeals court held that the defendant had no reasonable expectation of privacy in the van. "[T]he remote electronic monitoring of a vehicle's movement on a public road is considerably less intrusive than a physical search of the vehicle's interior that may result in the seizure of some of its contents." The court also argues that he has no expectation of privacy in his movements and noted that "[t]his is true particularly where the government's monitoring is short-term" (citing Alito's concurrence in Jones). Thus, the evidence was not suppressed though some of the convictions were vacated on other grounds.
In a dissenting opinion, Judge Eckerstrom held that the use of GPS to track a person "intrudes upon a person's reasonable expectation of privacy."
My colleagues maintain that our result in this case is compelled by the Court's reasoning in Knotts that a person has "no reasonable expectation of privacy in his movements" on public roads. 460 U.S. at 281. But, in the context we address today—the GPS tracking of a person's movements on public roads—five justices of the Court have implicitly declined to adopt that part of Knotts's reasoning. See Jones, 132 S. Ct. at 964.... I, therefore, cannot agree that this aspect of Knotts must control our reasoning in this case.Eckerstrom also declined to join Justice Alito in the belief that short-term monitoring would be constitutional without a warrant. "If we accept the premise that the sum total of a person's movements on a journey can disclose private features of their lives, then such private features may be discovered in monitoring of comparatively short duration as well as long."