¶42. concurring in part and dissenting in part. I agree with the opening paragraph of the majority decision that ‘"Vermont citizens have a constitutional right to privacy that ascends into the airspace above their homes and property” and that the “aerial surveillance in this case violated that constitutionally protected privacy right.” Ante, ¶ 1. Thus, I concur in the majority’s essential holding. But I cannot concur in the open-ended rationale or in the immediate consequence of that holding. Thus, I dissent in part.
¶ 43. As the majority acknowledges, this is a case of first impression, addressing a very important constitutional question. In these circumstances, it is critical that we write narrowly and provide as much predictability to citizens and law enforcement as possible. The essential question is when aerial surveillance will be considered a search. We do not serve the public interest if the answer to that seemingly simple question can be determined only in hindsight, after evaluating myriad factors. The majority states that it gives a clear answer by relying on the decisions “of our sister states and the United States Supreme Court.” Ante, ¶ 14. I fail to see how the majority decision offers that guidance, and, as I discuss below, the majority certainly does not rely on the decisions from other courts. In fact, it rejects virtually all other decisions on the question presented to us.
¶ 44. Acknowledging that its decision gives limited guidance to trial courts and law enforcement personnel and — I would add citizens — in the use of their property, the majority states that “no one factor need act as a litmus test of constitutionality.” Ante, ¶ 29. Then, in the course of the opinion, the majority goes on to cite almost a dozen separate factors: (1) the aerial surveillance took place over defendant’s curtilage, id. ¶¶ 16, 34; (2) the helicopter hovered for fifteen to thirty minutes, id. ¶ 18; (3) the helicopter hovered at an altitude of 100 feet, id.; (4) the altitude was illegal, id. ¶¶ 30-33; (5) the open land was posted, id. ¶ 27; (6) the officers were constitutionally forbidden to intrude at ground level, id. ¶ 33; (7) the helicopter created “undue noise, wind, or dust,” id. ¶ 27; (8) the surveillance was long, low and loud, id. ¶ 34; (9) the flyover was a “hazard to persons and *378property,” id. ¶ 31; (10) the flyover “targeted defendant,” id. ¶ 33; and (11) the flyover was conducted by trained law-enforcement officers in order to discover evidence of a crime, id. ¶ 34. The opinion makes no attempt to explain which of these factors are essential to its decision. It is not even clear under which circumstances the majority would find that aerial surveillance by law-enforcement officers is not a search.
¶ 45. The approach of the majority should be compared to those of other state courts. The leading cases are State v. Ainsworth, 801 P.2d 749 (Or. 1990); Commonwealth v. Oglialoro, 579 A.2d 1288 (Pa. 1990); and Henderson v. People, 879 P.2d 383 (Colo. 1994). The facts of Ainsworth are very similar to those in this case, except that, in that case, the helicopter was in a lawful location at the time of the observation of the marijuana plants. The court found this fact determinative, holding that, if the flyover did not violate “any common law or statutory rights of defendants, nor any rules, regulations, or other legal restrictions,” and, therefore, if the helicopter was in a lawful place, then the flyover was not a search under the Oregon Constitution. Ainsworth, 801 P.2d at 752. If a privacy intrusion was “purposive” as part of a criminal investigation aimed at the defendants, the court reasoned that this fact alone did not transform “a permissible observation into an unconstitutional search.” Id. at 753.
¶ 46. The court responded directly to arguments adopted by the majority here:
The state, defendants, and each of the Court of Appeals’ opinions in this case suggest that there are many factors to take into account in determining whether aerial observation constitutes a search under Article I, Section 9. Although they vary in terms of the number of elements to be considered and the emphasis to be placed on each element, all are unworkable as guidelines for law enforcement activities.
Id. at 754; see also State v. Wilson, 988 P.2d 463, 465 (Wash. Ct. App. 1999) (fixed-wing-aircraft overfly at above 500 feet, the FAA altitude limit, is not a search under the Washington Constitution).
¶ 47. The decision in Oglialoro is consistent with that in Ainsworth. In Oglialoro, the helicopter flew over a barn with a transparent roof, under which marijuana plants were growing. The court held that: “[a]s long as the police have the right to be where *379they are, and the activity is clear and visible, the fact that they are peering into curtilage is of no significance.” 579 A.2d at 1292. The court found that the helicopter hovered at fifty feet above the barn in order to determine whether the plants in question were marijuana plants and that flying at that altitude violated federal law because it was “a hazard to persons and property on the ground.” Id. at 1294. Thus, the court found that the surveillance was a search. Id.
¶ 48. Henderson adopted a virtually identical analysis. In that case, the helicopter flew over a shed behind the defendant’s house at an altitude of 500 to 700 feet, and in the shed, the officer in the helicopter observed plants that he identified as marijuana. The court first analyzed the case under the Fourth Amendment, relying on the plurality analysis in Florida v. Riley, 488 U.S. 445 (1988), and holding that the critical issue in the case was not the “number of times the helicopter passed over,” “the fact it was a helicopter,” or “how often . . . aircraft passed over the residence during the course of a year,” but instead “the fact that the marijuana was in plain view to anyone legally viewing the shed from the helicopter.” Henderson, 879 P.2d at 389. The court considered one other factor: that there was a limited degree of intrusiveness because of the limited duration, the altitude of the flight, and “little evidence of the noise, wind, dust, threat of injury, or interference with the use of the curtilage.” Id. at 390. Under Article II, Section 7 of the Colorado Constitution, because observation of what was plainly visible was not a search, the court held that observation of the curtilage from a lawful vantage point outside the curtilage was not a search. Id. at 390-91.
¶ 49. The majority claims that other decisions are “more nuanced,” ante, ¶ 24, or routinely consider a “multitude of factors,” ante, ¶ 26. To the extent this characterization is accurate, I do not believe that any of the post -Riley decisions support the majority’s multi-factored, open-ended analysis. The main example of consideration of a multitude of factors cited by the majority is Commonwealth v. One 1985 Ford Thunderbird Automobile, 624 N.E.2d 547 (Mass. 1993), decided under the Massachusetts Constitution. The decision is based on only two factors: the low altitude at which the helicopter flew and the fact that the flyover was not based on random surveillance, but instead on a detailed tip. Id. at 551. Ironically, the latter factor is not one of those cited by the majority here; indeed, the majority instead cites the *380targeted nature of the flyover as a factor showing that it was a search.
¶ 50. I have already covered most of the cases that the majority sees as applying a “more nuanced approach.” I would add that State v. Rodal, 985 P.2d 863, 867 (Or. Ct. App. 1999), is an intermediate court of appeals decision that must, and does, follow the Oregon Supreme Court decision in Ainsworth. See id.
¶ 51. In sum, I would reverse and remand on narrower and more specific grounds. First and foremost, we should acknowledge that a naked-eye observation10 from a properly conducted flyover, even if over a dwelling and curtilage, is not a search under Article 11. This is the holding of all of our precedents. Indeed, only a small handful of court decisions have ever found aerial surveillance to be a search and then have done so only in particularly intrusive situations.
¶ 52. Second, like the courts in Ainsworth, Henderson, and Oglialoro, I would condense the test and look essentially at only one factor: whether the observation was conducted from a lawful vantage point and was thus lacking in extraordinary intrusiveness. This factor is entirely consistent with our prior Article 11 analysis. In State v. Rogers, 161 Vt. 236, 248-49, 638 A.2d 569, 576 (1993), we held that police observation of marijuana growing in defendant’s garden within the curtilage is not a search if the officer is standing in a place from which observation is lawful, for example, in an unposted “open field.” Application of that principle here means that observation from a helicopter that is lawfully flying over defendant’s property is generally not a search. Defendant noted the consistency of this factor with our Article 11 jurisprudence in arguing that “the [Riley] plurality’s rationale makes a better fit with this Court’s Article 11 decisions than with the Fourth Amendment.”
¶ 53. Although I would also consider intrusiveness to respond to circumstances like those in Oglialoro where the actions of the helicopter involved extraordinary intrusiveness, this addition has no bearing on the facts of this case, because the applicable law requires that the helicopter stay at least 500 feet above the *381ground. I agree with defendant that this altitude is required by statute and by the regulations of the MERT program.
¶ 54. The majority objects that the altitude limits protect the safety, rather than privacy, interests of the citizenry. This is partially correct, but beside the point. Even if made from a lawful vantage point, an observation of objects or activities is just as intrusive as one from an unlawful point, irrespective of what makes the point of observation lawful or unlawful. The point is that the owner of the curtilage cannot consider to be unexpected an observation from a lawful vantage point and, therefore, has no reasonable expectation of privacy.
¶ 55. Applying this standard to the present situation, I acknowledge that it would have been better in this case if the trial court had determined whether the marijuana plants were within defendant’s curtilage, because such a question is a mixed question of fact and law on which the trial court’s determination is entitled to some deference. See Rogers, 161 Vt. at 241, 638 A.2d at 572. The evidence on this point comes from the officer’s affidavit that was filed with the information and that contains the result of the search warrant execution: that “the first location was along his garden fence” where twelve marijuana plants were found growing, that defendant brought the officer “to a location just south of the garden where 24 marijuana plants were . . . growing,” and that defendant finally showed the officer a lot “located south/east of the garden where 13 plant[s] were . . . growing.” During the flyover, the officer observed that the plants were “approximately 100 feet from the residence.” Although consistent with its generally vague approach, the majority is not clear on this point but appears to have concluded that the plants were in the curtilage. I think that is a reasonable conclusion. Defendant has generally argued that the plants were within the curtilage, and the State has not directly disputed that characterization. The facts here on this point are very similar to those in Rogers, where we upheld a trial court conclusion that the plants were within the curtilage. See id. at 241-43, 638 A.2d at 572-73.
¶ 56. I would not rule in this case on the standard for aerial observations of open fields that are posted on the ground. There are arguments on both sides of this question that are only superficially explored in the briefing. The trial court specifically refused to find whether the officer who made the aerial observation was aware of the posting. Again, because of the breadth and *382lack of specificity in the majority opinion, it is impossible to determine whether that opinion purports to address this question. For now, I would limit this decision to observation of the dwelling and curtilage.
¶ 57. This leads me to the second ground of disagreement with the majority decision. The majority has ruled that the warrant “was obtained solely on the basis of the aerial observations,” ante, ¶ 40, and reversed defendant’s conviction as a result. Since the majority refuses to specify which part of the observations constituted a search under Article 11, that ruling is logical, but it also an example of why the majority’s overbroad approach is inconsistent with the applicable law.
¶ 58. Answering the question about whether state conduct violated defendant’s constitutional rights does not, in itself, decide what the remedy for the violation should be. The remedy invoked here is to suppress the marijuana evidence. This remedy may be invoked, however, only if there is a causal connection between the constitutional violation and the obtaining of the evidence. See Segura v. United States, 468 U.S. 796, 804-05 (1984) (explaining application of causation, or independent-source doctrine, in Fourth Amendment cases); see also United States v. Ramirez, 523 U.S. 65, 72 n.3 (1998) (application of the exclusionary rule depends on the existence of a “sufficient causal relationship” between the unlawful conduct and the discovery of the evidence). The exclusionary rule prohibits the introduction of evidence directly resulting from unconstitutional conduct and also “prohibits the introduction of derivative evidence . . . that is the product of the primary evidence, or that is otherwise acquired as an indirect result of the unlawful search, up to the point at which the connection with the unlawful search becomes ‘so attentuated as to dissipate the taint.’ ” Murray v. United States, 487 U.S. 533, 536-37 (1988) (quoting Nardone v. United States, 308 U.S. 338, 341 (1939)); accord Wong Sun v. United States, 371 U.S. 471, 484-85 (1963). The exclusionary rule does not apply to evidence that is obtained through an independent source. See Murray, 487 U.S. at 538-39. The exception is designed to prevent too much evidence from being excluded, because “[w]hen the challenged evidence has an independent source, exclusion of such evidence would put the police in a worse position than they would have been in absent any error.” Nix v. Williams, 467 U.S. 431, 443 (1984). We have recognized the independent-source doctrine in State v. Phillips, *383140 Vt. 210, 218, 436 A.2d 746, 750-51 (1981), and State v. Dupaw, 134 Vt. 451, 454, 365 A.2d 967, 968 (1976) (stating that the exclusionary rule applies only insofar as “‘knowledge gained by the Government’s own wrong cannot be used by it.’ ”) (quoting Silverthorne Lumber Co. v. United States, 251 U.S. 385, 392 (1920)).
¶ 59. A good example of the importance of the causation requirement comes from State v. Rodal, where the defendant argued that photographs taken from a helicopter with a telephoto lens turned a permissible flyover into a search. The court answered that the officer observed the marijuana plants before he photographed them, and that his observation, apart from the photographs, was sufficient to allow officers on the ground to locate the plants. Rodal, 985 P.2d at 867. Thus, the naked-eye observation was an independent source of the identification of the marijuana. See also State v. Marolda, 927 A.2d 154, 164 (N.J. Super. Ct. App. Div. 2007) (under New Jersey Constitution, low flight over “the residence and curtilage was preparatory and incidental to location and observation of cornfields, which are not constitutionally protected”).
¶ 60. The trial court in the instant case found that “the helicopter was flying at less than 500 feet at various times during the flight in question, and at times as low as 100 feet above the ground.” Because the court held that there was no constitutional violation, the court did not, however, relate the altitude of the helicopter to the observation of the marijuana. The majority has not attempted to clarify the point. Indeed, because the majority will not explain which conduct made the flyover a search, it is impossible to determine causation as required.
¶ 61. The record indicates that the officer understood that he was required to make a naked-eye observation of marijuana from above 500 feet. If he made such an observation before the helicopter came below that altitude over defendant’s house and curtilage, there may have been an independent and lawful search that obtained the information defendant is seeking to suppress. I would remand for determination of when the crucial observation was made rather than holding the search to be constitutionally defective and reversing defendant’s conviction. It may well be that the constitutional violation and the observation of the marijuana are inextricably intertwined, but the majority has acted prematurely in so ruling.
*384¶ 62. The majority has answered that the State never put causation in issue and therefore that we must act, as a matter of law, as if the question of causation were resolved in defendant’s favor. In fact, the State never had the burden to put causation in issue. In this case, since the State’s position was that the officers acted lawfully, the State had no reason or ability to speculate on how the officers’ conduct might be found to be unlawful and how causation would be established. The fact is that no court, not this Court or the district court, has found that the constitutional violation caused the observation of the marijuana, and defendant has therefore escaped entirely his burden of proof.
¶ 63. In summary, I carry no brief for aerial surveillance as part of a marijuana eradication program. There is a legitimate policy debate about whether such surveillance is a good use of limited law enforcement resources, but that debate should be resolved as a matter of policy, not constitutional law. My disagreement with the majority lies in its assertion that it has written “narrowly” by refraining from ruling based on the altitude of the helicopter and by relying instead upon the totality of the circumstances. By relying on a multitude of factors, most of which are irrelevant to whether a search occurred here, and by refusing to assign any particular weight to any factor, the majority has painted with the broadest brush imaginable, far broader than any other court in the land. Every factor the majority introduces into the analysis makes the grounds for its decision broader. This is not narrow decision making. Increasingly, we are using rationales in Article 11 cases that require the intervention of this Court before it can be determined whether law enforcement conduct was lawful, because no law-enforcement officer, citizen, or trial court judge could ever predict what we will ultimately decide. Professor LaFave has explained the problem with an approach like the majority’s as follows:
The basic premise is that Fourth Amendment doctrine, given force and effect by the exclusionary rule, is primarily intended to regulate the police in their day-to-day activities and thus ought to be expressed in terms which are readily applicable by the police in the context of the law enforcement activities in which they are necessarily engaged. A highly sophisticated set of rules, qualified by all sorts of ifs, ands and buts and requiring the drawing of subtle nuances and hairline distinctions, may be the *385sort of heady stuff upon which the facile minds of lawyers and judges eagerly feed, but they may be literally impossible of application by the officer in the field.
If the rules are impossible of application by the police, the result may be the sustaining of motions to suppress on Fourth Amendment grounds with some regularity, but this can hardly be taken as proof that the people are secure in their persons, houses, papers, and effects, against unreasonable searches and seizures. Rather, that security can only be realized if the police are acting under a set of rules which, in most instances, make it possible to reach a correct determination beforehand as to whether an invasion of privacy is justified in the interest of law enforcement. In short, we must resist the understandable temptation to be responsive to every relevant shading of every relevant variation of every relevant complexity lest we end up with a [F]ourth [AJmendment with all of the character and consistency of a Rorschach blot.
2 W. LaFave, Search and Seizure § 5.2(c), at 448-49 (2d ed. 1987) (footnotes and internal quotations omitted). The rule announced by the majority today falls into precisely the trap Professor LaFave outlines. No one, be it the trial courts, law-enforcement officers, or the citizens of this state will consistently be able “to reach a correct determination beforehand as to whether an invasion of privacy is justified” under similar circumstances. Id. I do not think we administer justice with such an approach, and we hardly guarantee to “the people” that they will be secure in “their persons, houses, papers, and effects, against unreasonable searches and seizures.” Id. (quotations omitted).
¶ 64. I would reverse and remand, but on a much narrower rationale, fully consistent with the precedents from this Court and courts in other jurisdictions, thus giving better guidance to trial courts, ordinary citizens, and law enforcement. Thus, although I concur that the helicopter observation violated defendant’s rights, I cannot approve of the majority’s mode of constitutional analysis or of the remedy it imposes.
Although the majority does not mention the issue explicitly, I would leave to another day the issue of enhanced observation by binoculars or more advanced technology. See State v. Rogers, 161 Vt. 236, 245-46, 638 A.2d 569, 574-75 (1993) (leaving open the question of whether observation of the curtilage from a lawful vantage point is a search if aided by binoculars or technology).