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This post was going to have the title of “Court of Appeals discovers speed of light,” but that was really only half of the battle in State v. Branch, A140217 (June 1, 2011), see here. It is surprising that despite the common use of laser speed guns (e.g., see here), no Oregon appellate court had yet determined the validity of “lidar” technology (like radar, but with laser light instead of radio waves). In Branch the issue was whether the criminal defendant sold drugs within 1,000 feet of a school (in this case, McCoy Academy, an alternative charter school). After the defendant’s arrest, the police went to the locations of the various undercover drug buys, and lased the distance to the school at about 300 and 400 feet. The panel unanimously agreed that lidar could be found valid on appeal, but the concurrence raised some basic and valid questions about judicial notice on appeal.

At trial, the defendant objected not to the accuracy of the particular device, apparently, but to the fundamental nature of laser rangefinding technology under OEC 702, State v. Brown, 297 Or 404, 687 P2d 751 (1984), and State v. O’Key, 321 Or 285, 899 P2d 663 (1995). His foundation objection to the introduction of the rangefinder evidence was based on the police officer’s inability to discuss the principles of how the lidar device worked, or that the technology itself was reliable in a scientific sense. In essence, the defendant was challenging the speed of light.

By way of background, the panel discussed how lidar devices worked in principle. A laser beam is generated by the device, and sends out measured pulses every few milliseconds. The device then captures the reflection of those pulses and computes the time it took to bounce back. The speed of light is one of nature’s few absolute and constant limitations, being around 186,000 miles per second (~300,000 km/sec) in a vacuum, and only imperceptibly slower in the Earth’s atmosphere. As the court put it, “the distance evidence proffered by the state is based on the premise that measurements of distance can be derived through the lidar device’s use of a certain scientific principle, viz., the speed of light.” As a practical matter, this means that in order for the school to be farther away from the drug buys based on the method of measurement (as opposed to simply the accuracy of the device), the lidar would have to achieve faster-than-light travel with the beam. If the 300 and 400 feet measured by the police were actually over 1000 feet away, the laser beam would have to be sped up by at least 3.3 and 2.5 times the speed of light, respectively.

The court recognized that equations based on the speed of light were fundamentally scientific, and therefore potentially subject to the scientific evidence test articulated in Brown. To admit scientific evidence, Brown normally requires relevancy under 401, helpfulness under OEC 702, and lack of unfair prejudice under OEC 403. Interestingly, the court noted that this test “is not applicable in every case involving the admissibility of scientific evidence ... [where it is] a clear case, a case for judicial notice, or a case of prima facie legislative recognition.” (citation and internal quotation marks omitted). Thus in the case before it—without prior cases or statutes to rely on—the court needed to determine “whether the scientific validity of lidar-device evidence is clear or can be established through judicial notice[.]”

The majority found that the reliability of light-based measurements was clear because the speed of light is a fundamental universal constant, citing to a scientific reference work on universal constants put out by the National Institute of Standards and Technology. The court also noted testimony below of “13 years” of use of lidar by the Portland Police, as well as the court’s independent recognition of lidar’s “widespread, everyday use in multiple contexts, including its pervasive use as a replacement for tape measures in construction projects and as a measuring device for surveying purposes.” Interestingly, it is not clear where the recognition of its “widespread” and varied use was found, and judicial notice of certain facts was not taken until later in the opinion. Still, the court held that in this “clear case,” the validity of using light to measure distance was “indisputably valid,” and “the state was not required to present foundational evidence” for the validity of lidar measurements.

The majority then bolstered its initial finding by formally taking judicial notice of facts underlying lidar. The entire panel agreed that OEC 201 did not govern their taking of judicial notice on appeal, because the facts governing admissibility of evidence were not “adjudicative facts.” Relying on the prior discussion of scientific validity, the majority formally adopted the facts surrounding lidar technology under an inherent power of judicial notice.

The concurrence by Presiding Judge Hazelton was notable for its forthrightness in noting that the procedure used to validate lidar, in absence of a foundation of scientific validity on the record, was troubling. Judge Hazelton was reassured by the Oregon Supreme Court taking notice of several facts outside the record in Brown, the lack of any true dispute from the defendant as to the actual reliability of lidar, and the perceived need to uphold the validity of this commonly used tool because as Judge Hazelton noted, “there [may] be no occasion to issue an appellate opinion settling the matter.” It is this last reason that is perhaps most concerning.

Although the speed of light is not reasonably subject to dispute, the methods of calculation, consistency, and accuracy of specific lidar devices are not a given. The admission that the decision was to an extent results-oriented should give pause, especially since the majority’s opinion on its face allows a trial court to admit anything it considers “indisputably valid.” Mere widespread adoption and the passage of time does not make a potentially flawed tool work any better. Nor is a court in a position to say what is or is not “indisputable” with respect to all but the most basic of fact questions. Lidar is certainly valid in principle, but a court should never justify its exercise of legislative authority by citing to expediency.