Should The Police Be Allowed To Attach A GPS Tracking Device To Your Car Without A Warrant ?

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.

  • UCrawford


    I’m going to go out on a limb and say that the courts are going to side with the defendent here…and the police handling the case should be fired (even though they likely did catch a rapist). The police, without warrant, essentially placed a tap on the vehicle. Sure, the guy is likely guilty of the crimes…but what if he wasn’t? What if he’d had nothing to do with it? What if the cops had bugged the car of an innocent person and tracked where that person went, who he talked to, what his business was? If the police are allowed to circumvent the warrant process as a matter of convenience in this case, what’s to stop them from doing it in other cases where maybe the motive isn’t to stop a criminal but to engage in harassment of law-abiding citizens because of department corruption, like what happened in Manassas, VA?

    Once you ignore the police violating civil liberties to catch someone who probably merited being pursued, you open the door to allow police to do it to people who don’t deserve it as well…and I have a hard time believing the courts are going to miss a point that obvious.

    And it’s unbelievable that the cops in Fairfax County didn’t realize that this would come back to sink their case either. They had probable cause…they couldn’t go talk to a judge or prosecutor and get a warrant for this? I generally appreciate the police, believe they’re necessary and understand that their job can be difficult, but either the cops’ evidence on this suspect was so weak that they knew there was no way they’d get a warrant or the police officers of Fairfax County are some of the dumbest fucking people on the planet (and that’s saying a lot).

    Also, I suspect that even if Foltz is exonerated he’s not going to go free as the state will likely do what it can to have him committed to psychiatric care. Best of all possible worlds, the courts rule against the police, Foltz gets committed to an institution, and the police responsible are either suspended or fired.

  • KipEsquire

    I blogged about a similar post-Knotts case a while back.

  • UCrawford


    Here’s hoping that the court that takes this case is more sane than the one you wrote about, then.

  • Doug Mataconis


    While I think we both agree on how this case should be decided, do you agree with me that, given the current make up of the Supreme Court and their rulings to date on 4th Amendment issues, that the Supremes would be unlikely to declare this an illegal search and seizure ?

  • Brad

    Having been a police officer for five years, I can definitely comment from a legal standpoint. It’s simple: If an officer has information to believe that a crime has been, is being, or will be committed, he should have the right to attach a GPS tracking to the vehicle.

    The same rule already applies to vehicle searches, which by the way, police don’t need a warrant for during a traffic stop. Applying a GPS Tracking System to a vehicle is less intrusive than a physical search of the vehicle or suspect. So, why wouldn’t gps tracking by police be permissible without a warrant?

  • UCrawford


    It’s simple: If an officer has information to believe that a crime has been, is being, or will be committed, he should have the right to attach a GPS tracking to the vehicle.

    Police officers don’t have rights, individuals have rights. Police officers have jobs. The police officer’s job is to uphold those laws that protect individual rights and to defer to the courts’ judgment when those rights need be infringed upon in the enforcement of those laws.

    Semantics on “rights” aside, I’ve got no problem with your argument that police should have the authority to put a GPS on a suspect’s car as long as they present the probable cause to a judge and get a warrant to do so. When officers, however, decide that they’re the ultimate arbiters of what our rights are and feel they don’t need to go through the court system to seek permission when they violate individuals’ rights in the course of an investigation then those police officers are nothing more than vigilantes and criminals themselves.

    The officers in this case were wrong because they were lazy and because they cut corners in doing their job, and as such may have helped to allow a known sex offender to get away with what he’s done (if he gets competent counsel) by using tainted evidence…and if they get away with their tactics they’ve undermined the rights of law-abiding citizens in the process. The officers in this case deserve to lose their jobs for what they’ve done, even if they thought they were doing it for the right reasons.

  • trumpetbob15

    I am not a lawyer, but wasn’t the cop guilty of tampering with private property. Wouldn’t the cop have had to physically touch the car to attach a device?

    I see that as the difference between this situation and the Knotts case. The Knotts case was more of a sting operation, installing a tracking device with the “current” owner’s permission. In this instance, the cop essentially vandalized a private citizen’s car and the case should be decided with that in mind, even if most people would want it to be otherwise.

    A cop that breaks the law is no better than the criminal he is trying to stop.

  • Ted

    While I personally find it objectionable, as it is one step closer to a police state, considering other things allowed, I’d have to say it is legal, baring individual state legislation.

    It is legal to follow a vehicle, and externally monitor it. As long as the device is external and causes no damage(i.e. mounting damage, drain on power, etc) then it should be legal.

    I know in my state it is legal for people to lift your wiper blade and place advertisements on your windshield, using the wiper to pin it. As long as the wiper is not damaged, it is legal.

    If the police use a magnetic gps tracking device on the under carriage of the vehicle, then I suppose it is about as damaging.

    As was pointed out, following a signal is not considered an invasion of privacy, nor do you have an expectation of privacy as to where you go when you are driving.

    Just my 2 cents.