An interesting Constitutional question from Northern Virginia:

When Fairfax County police were trying to catch a man last month who had molested 11 women, they examined the Virginia sex offender registry and found a possible suspect. They looked at his background, which included a series of similar assaults, and his residence, which was not far from where the attacks were occurring. Then, to try to catch him in the act, police slipped a small Global Positioning System device inside the bumper of the van driven by the suspect and began tracking him — without a search warrant and without consulting a prosecutor. The tactic, officers say, was an almost instant success. The GPS device placed the van driven by David L. Foltz Jr., 40, in the vicinity of a sexual assault Feb. 5. And when officers began surveilling Foltz the next day, a Fairfax detective saw him drag a woman into a dark area in Falls Church and attack her. The officer rescued the woman and arrested Foltz. Foltz’s attorney, Chris Leibig, said yesterday in Falls Church General District Court that placing the tracking device on the vehicle was a violation of Foltz’s protection against unreasonable search and seizure. Arlington County General District Court Judge Richard J. McCue disagreed, denying Leibig’s motion to suppress police testimony about events that occurred after the device was placed on Foltz’s van. In the preliminary hearing that followed, a 46-year-old Falls Church woman testified that she was grabbed from behind and pulled into a dark area. Detective Matthew Charron said he saw the attack and knocked Foltz off the woman. McCue certified Foltz’s charges of abduction with intent to defile and sexual battery for the Arlington grand jury, which meets next week. Foltz has not been charged in any of the 11 other similar assaults that have occurred in Fairfax and Alexandria, but police said no similar attacks have happened since he was arrested

The operative part of the Constitution is, quite obviously, the 4th Amendment:

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.

So, the question really is whether placing a Global Positioning System (GPS) tracking device on a vehicle parked on a public street and tracking that vehicle on public streets is either an “unreasonable” search and seizure or if it is even a search or seizure requiring a warrant at all.

There is one Supreme Court case that comes close to being applicable to the facts of this case. In United States v. Knotts (1983), the Supreme Court was asked to rule on the following case:

Having reason to believe that one Armstrong was purchasing chloroform to be used in the manufacture of illicit drugs, Minnesota law enforcement officers arranged with the seller to place a beeper (a radio transmitter) inside a chloroform container that was sold to Armstrong. Officers then followed the car in which the chloroform was placed, maintaining contact by using both visual surveillance and a monitor which received the beeper signals, and ultimately tracing the chloroform, by beeper monitoring alone, to respondent’s secluded cabin in Wisconsin. Following three days of intermittent visual surveillance of the cabin, officers secured a search warrant and discovered the chloroform container, and a drug laboratory in the cabin, including chemicals and formulas for producing amphetamine. After his motion to suppress evidence based on the warrantless monitoring of the beeper was denied, respondent was convicted in Federal District Court for conspiring to manufacture controlled substances in violation of 21 U.S.C. 846. The Court of Appeals reversed, holding that the monitoring of the beeper was prohibited by the Fourth Amendment.

The Supreme reversed the holding below and upheld the conviction:

Monitoring the beeper signals did not invade any legitimate expectation of privacy on respondent’s part, and thus there was neither a “search” nor a “seizure” within the contemplation of the Fourth Amendment. The beeper surveillance amounted principally to following an automobile on public streets and highways. A person traveling in an automobile on public thoroughfares has no reasonable expectation of privacy in his movements. While respondent had the traditional expectation of privacy within a dwelling place insofar as his cabin was concerned, such expectation of privacy would not have extended to the visual observation from public places of the automobile arriving on his premises after leaving a public highway, or to movements of objects such as the chloroform container outside the cabin. The fact that the officers relied not only on visual surveillance, but also on the use of the beeper, does not alter the situation. Nothing in the Fourth Amendment prohibited the police from augmenting their sensory faculties with such enhancement as science and technology afforded them in this case.

In that case, though, the Supreme Court did not rule on the issue of whether the act of placing the tracking device on an automobile without a warrant and probable cause would violate the 4th Amendment and the courts that have ruled on the issue seem to be all over the place:

A Wisconsin district court held, earlier this year, that officers must have reasonable suspicion to believe that a crime is being/has been committed and that the installation of the tracking device will yield evidence of that crime. U.S. v. Garcia, 2006 WL 298704 (W.D. Wisconsin 2006). This court found that reasonable suspicion was enough because “the intrusion caused by the application of the device is minimal. The real intrusion . . . is the 24/7 governmental monitoring that follows.” (…) A couple of years ago, a New York court went further. In People v. Lacey, 787 N.Y.S.2d 680 (N.Y. Co. Court 2004), the court held that police must get a warrant, based on probable cause, to install a tracking device” “Although . . . persons have diminished expectations of privacy in automobiles on public roads and can be visually tracked by the police, it is clear that the mere act of parking a vehicle on a public street does not give law enforcement the unfettered right to tamper with the vehicle by surreptitiously attaching a tracking device without either the owner’s consent or without a warrant issued by a Court. . . . Attachment of the GPS requires a physical intrusion into an individual’s personal effects . . . . Accordingly, the Court finds that in the absence of exigent circumstances, not here present, the police should have obtained a warrant prior to attaching the GPS to the Mitsubishi.” About a month ago, a New Jersey court held that the 4th Amendment requires police to get a warrant before attaching a GPS tracking device. State v. Scott, 2006 WL 2640221 (N.J. Super. A.D. 2006). (…) Other courts have disagreed, basically on the premise that the installation of a GPS tracking device in no way interferes with the vehicle owner’s possession and use of the vehicle. As the Ninth Circuit said in U.S. v. McIver, 186 F.3d 1119 (1999), “McIver did not present any evidence that the placement of the . . . tracking devices deprived him of dominion and control of his Toyota 4Runner, nor did he demonstrate that the presence of these objects caused any damage to the electronic components of the vehicle. Under these circumstances, we hold that no seizure occurred because the officers did not meaningfully interfere with McIver’s possessory interest in the Toyota 4Runner.”

The case at hand is a hard one to make a general rule from. There’s no question that Foltz is guilty of at least one attempted sexual assault because the cops caught him in the act thanks to the GPS tracking device. He may well have committed the eleven other assaults that the police were investigating when they focused on him.

But if the police violated his Constitutional rights in the process, none of that matters.