STATE OF MINNESOTA

IN COURT OF APPEALS

A15-1984

State of Minnesota,

Respondent,

vs.

Shane Lee Olson,

Appellant.

Filed December 5, 2016

Affirmed

Ross, Judge

Sherburne County District Court

File No. 71-VB-15-3373

Lori Swanson, Attorney General, St. Paul, Minnesota; and

Derek T. Archambault, Hawkins & Baumgartner, P.A., Anoka, Minnesota (for respondent)

John D. Ellenbecker, St. Cloud, Minnesota (for appellant)

Considered and decided by Cleary, Chief Judge; Worke, Judge; and Ross, Judge. 

S Y L L A B U S

A police officer’s controlled testing of a handheld laser speed-measuring device to 

establish that it is accurately measuring distance to a stationary object satisfies the 

foundational external-test requirement of Minnesota Statutes section 169.14, subdivision

10(a) (2014), allowing the district court to admit into evidence the officer’s testimony of 

the device’s speed readings. 
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O P I N I O N

ROSS, Judge

A police officer used a handheld laser device and clocked Shane Olson’s car at 70 

miles per hour in a 55-mile-per-hour zone. Olson challenged the ticket in court and objected 

to the admission of the officer’s testimony of his speed. He argued that the officer’s external 

testing of the laser unit failed to verify its reliability because the officer’s testing proved 

only that the unit accurately measures distance, and speed depends on an accurate measure 

of both time and distance. The district court overruled the objection and found Olson guilty. 

Because the officer’s external test verified not only that the laser unit was measuring 

distance accurately but also implicitly verified that it was measuring time accurately, the 

district court did not abuse its discretion by admitting the officer’s testimony of the speeddevice evidence, and we affirm.

FACTS

Elk River police officer Andrew Zabee ticketed Shane Olson for speeding in July 

2015. Officer Zabee testified at Olson’s bench trial that Olson’s car was traveling in a 55-

mile-per-hour zone when the officer’s handheld laser device indicated that Olson was 

moving at 70 miles per hour. Olson objected to the officer’s testimony, contending that it 

lacked a proper evidentiary foundation, and the district court sustained the objection. The 

prosecutor questioned Officer Zabee further, and the officer testified that he was trained to 

use the laser device, that his car was stationary when he encountered Olson’s car, that he 

pointed the laser device out his open window to avoid any distortion, and that the weather 

conditions were suitable for interference-free measurements by the device.
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Olson again objected for lack of foundation, arguing that the officer’s testimony 

failed to satisfy the external-test requirements of Minnesota Statutes section 169.14, 

subdivision 10(a)(4), which allows an officer to testify to a reading from a speed-testing 

device only if the officer first establishes that he performed an external test to verify that 

the device was functioning reliably. The district court asked Officer Zabee, “Are there any 

external tests done on this laser that you’re aware of?” The officer answered, “No.” The 

district court implicitly agreed with Olson that the state had not laid the proper testimonial 

foundation.

The prosecutor questioned Officer Zabee again. The officer testified that the device 

ran its own internal test when he activated it. He then performed an external “distance 

check.” He explained that he successfully performed the distance check by targeting an 

object at a known distance from the unit, triggering the unit, and verifying that the distance 

displayed on the unit accurately matched the known distance. The district court then 

accepted the officer’s testimony that the laser unit calculated Olson’s speed at 70 miles per 

hour.

Olson cross-examined Officer Zabee. The officer admitted that he performed no 

separate test to establish that the device accurately measures speed. Olson again raised his 

foundational challenge and argued that the officer’s testimony did not satisfy the statute 

because speed is calculated based on distance and time, not just distance. The prosecutor

argued that the state has “never been required to prove up some sort of accurate 

measurement of time” for traditional radar units, so it need not prove time for the laser unit. 
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The district court held that Officer Zabee’s distance check satisfied the foundational 

requirements for speed-device evidence. It reasoned that section 169.14, subdivision 

10(a)(4), does not specify that an external test is required “for every different component 

of whatever formula the device is using.” It found Olson guilty of speeding. Olson appeals.

ISSUE

Does the district court act within its discretion and in compliance with Minnesota 

Statutes section 169.14, subdivision 10(a), when the court allows an officer to state a 

defendant’s speed based on the reading indicated on a laser device that the officer 

externally tested only for its ability to accurately measure distance to a stationary object?

ANALYSIS

Olson asks us to reverse based on the purportedly erroneous evidentiary ruling. We 

review a district court’s evidentiary rulings for an abuse of discretion. State v. ChavezNelson, 882 N.W.2d 579, 588 (Minn. 2016). We will reverse only if the appellant 

establishes that the district court’s ruling reflects an abuse of discretion and that the ruling 

prejudiced his substantial rights. Id. Olson argues specifically that the district court should 

not have admitted Officer Zabee’s testimony that the laser device indicated that he was 

traveling at 70 miles per hour because the officer did not sufficiently test the unit. We think 

Olson is wrong on the law and the science. 

Olson contends that the prosecutor failed to lay adequate foundation for the officer’s

laser-result testimony. The relevant statute imposes four conditions before a district court 

may admit evidence of speed measured by a laser unit or other speed-measuring device:

(1) the officer operating the device has sufficient training to 

properly operate the equipment;

(2) the officer testifies as to the manner in which the device 

was set up and operated;
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(3) the device was operated with minimal distortion or 

interference from outside sources; and

(4) the device was tested by an accurate and reliable external 

mechanism, method, or system at the time it was set up.

Minn. Stat § 169.14, subd. 10(a). The constitutionality of this legislative evidentiary 

requirement is not contested here, but, relevant to our application of the statute, we have 

held that “because [section] 169.14 complies with, rather than conflicts with, the rules of 

evidence, it does not violate the separation-of-powers doctrine.” State v. Ali, 679 N.W.2d 

359, 365 (Minn. App. 2004).

Olson argues that the state failed to satisfy the fourth element of the foundational 

requirement—the completion of an external test “by an accurate and reliable external

mechanism, method, or system.” He is wrong for two reasons. The first is that the statute 

does not require an external test to verify the precision of every component of a speedmeasuring device’s calculation of speed. The second is that, even if it did, a distancemeasurement check of a standard laser unit meets that requirement. 

Caselaw regarding laser evidence is less developed than caselaw for radar evidence, 

but we have observed that the admissibility of laser evidence is analogous to the 

admissibility of radar evidence. Ali, 679 N.W.2d at 365. Police test traditional squad-car 

radar devices externally without necessarily measuring the speed of a moving physical 

object; they can verify the device’s accuracy by measuring the frequency of its radiating 

waves as modulated by a calibrated, vibrating tuning fork. State v. Gerdes, 291 Minn. 353, 

357–60, 191 N.W.2d 428, 431–33 (1971). Olson does not identify any case that requires a 

more specific external test to satisfy subdivision 10(a)(4), and we have found none. See
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State v. McDonough, 302 Minn. 468, 470, 225 N.W.2d 259, 260 (1975) (holding that radar 

device’s internal tuning fork serves as an adequate check on accuracy of external tuning 

fork); State, City of St. Louis Park v. Bogren, 410 N.W.2d 383, 385 (Minn. App. 1987) 

(stating that “use of properly calibrated internal and external tuning forks serves [as] an 

adequate test of radar accuracy”); State v. Dow, 352 N.W.2d 125, 127 (Minn. App. 1984) 

(affirming admission of officer’s testimony of radar results when tuning fork and calibrated 

speedometer on squad car were used to check radar’s accuracy). We have declared that the 

purpose of testing the radar unit is to determine that the mechanism is generally operating 

properly, not to determine that it is operating properly in every mode. State v. Pulos, 406 

N.W.2d 75, 76 (Minn. App. 1987) (rejecting an argument that a radar device must be retested every time it is shifted from “moving” to “stationary” mode). And as to a laser device 

specifically, we rejected the argument that testing the device on a moving object is required 

to satisfy the statute’s external-test condition. Ali, 679 N.W.2d at 366. Under the caselaw, 

subdivision 10(a)(4) requires only that a device be tested by an “accurate and reliable” 

external method before an officer may testify about its results. See id.

This caselaw about the admissibility of speed-device evidence—particularly our Ali

case—is informative. It teaches that we have never interpreted the statute so as to preclude 

an officer’s speed-device-results testimony simply because the officer’s external testing 

was not scientifically exhaustive. A defendant is of course free to attempt to impeach the 

officer’s testimony by criticizing the imprecise testing methodology and consequently 

calling the unit’s reliability into doubt. See Minn. R. Evid. 607 (“The credibility of a 

witness may be attacked by any party . . . .”). But there is a substantial difference between 
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testimony that is insufficiently reliable to be convincing (an ultimate decision for the factfinder) and testimony that is insufficiently reliable merely to be admitted (a preliminary 

decision of law for the court). This is where our reasoning in Ali is particularly useful. 

Again, we explained that the legislative foray into evidentiary foundations for trial 

testimony does not unconstitutionally cross the separation-of-powers line specifically 

because the statute “complies with, rather than conflicts with, the rules of evidence” as to 

foundational admissibility. Ali, 679 N.W.2d at 365. Olson essentially urges us to apply the 

statute to prohibit an officer from testifying about the laser unit’s speed calculation unless 

the officer’s earlier external testing covers every element of the unit’s speed calculation. 

Not only does the express language of the statute (calling for “an accurate and reliable 

external [testing] method”) not demand this sort of exhaustive testing, an exhaustivetesting obligation would also far exceed the judicially developed foundational 

requirements. Because we have already interpreted the statute as providing an admissibility 

rule that is consistent with rather than more restrictive than judicial foundational 

requirements for non-expert witnesses, we will not now interpret it as imposing a more 

formidable admissibility prerequisite. The caselaw convinces us that the limited, external 

distance test for proper laser-unit functionality clears the statutory hurdle even if a more 

exacting and probative accuracy test is conceivable.

Officer Zabee’s testing of the device is at least such a sufficient test. Olson does not 

argue that the officer’s external distance check was inaccurate or unreliable, only that some 

additional test for time must also have been performed before the officer could testify to 

what the device indicated about Olson’s speed. Olson does not propose an additional, 
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independent external test that would verify specifically the accuracy of the device’s use of 

time. And we can think of none. We are convinced that he has failed to demonstrate that 

the district court abused its discretion by admitting the evidence. 

Olson’s argument also depends on a misunderstanding of the science of standard 

laser devices. So even if Olson is correct that the statute requires an officer to complete an 

external test of a laser unit for both time and distance before the officer may testify about 

the device’s calculation of a defendant’s speed, still we reject his appeal. This is because, 

as a matter of basic physics, Officer Zabee’s distance check necessarily tested for both

distance and time. And as such, the distance check is an “accurate and reliable external . . . 

method” to measure an object’s speed. 

Reviewing how now-customary laser devices work informs us that, when a laser

device accurately calculates distance, it necessarily is also accurately measuring time. 

Olson correctly states that the accuracy of a speed calculation depends on the accuracy of 

both a time and distance measurement. But he overlooks the fact that a laser device first 

calculates an object’s distance from the device in order to calculate its speed. See 1 

McCormick on Evidence § 204(D) (Kenneth S. Broun, ed., 7th ed., June 2016) (explaining 

laser-based speed-measuring technology, stating that the physical principles the technology 

relies upon are “eminently sound,” and referencing multiple jurisdictions that have 

expressly accepted the general reliability of laser technology); see also Datta Sainath 

Dwarampudi & Venkat Sai Vivek Kakumanu, Efficiency of a LiDAR Speed Gun, 1 Int’l J. 

of Electrical, Electronics & Data Comm. 27, 27–28 (2013); Ryan V. Cox & Carl Fors, 

Admitting Light Detection and Ranging (LiDAR) Evidence in Texas: A Call for Statewide 
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Judicial Notice, 42 St. Mary’s L.J. 837, 849 (2011); see cf. Ali, 679 N.W.2d at 364 

(indicating that a district court taking judicial notice of the general reliability of laser 

technology would not be an abuse of discretion). 

Understanding how a laser device accurately calculates a known distance

establishes the reliability of its time measurement. A laser unit measures distance

specifically based on the constant speed of light and based on the time it takes for pulsed, 

infrared light to reflect off the target and return to the device. See Efficiency of LiDAR at 

28; Admitting LiDAR at 849. The device calculates distance by multiplying half the 

reflection time by the invariable speed of light. See Efficiency of LiDAR at 28. Therefore if 

a laser device measures a known distance to an object accurately, it must necessarily be 

measuring the time taken for light to travel to and return from that object accurately. To 

calculate the speed of the object if it were moving, the device would then divide the object’s 

change in distance between pulses of light by the amount of time elapsed between those

same pulses. Id.; see also Admitting LiDAR at 849. And if the device’s measurement of 

time is shown to be accurate as to its calculation of distance, there is no reason to assume 

that its measurement of time would be inaccurate as to its calculation of speed.

Olson’s challenge is therefore met: because the laser unit was accurately calculating

distance, it was also accurately measuring time and speed. There was no need for the officer 

to additionally test the pulse-interval component of the unit by also testing it on a moving 

object. We recognize that one certainly could test the device on a moving object, like a car 

with a verified speedometer, and that this additional test would bolster the trustworthiness 

of the officer’s laser-results testimony. And we understand that the unit’s ability to 
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precisely and accurately calculate the time that lapses between each of its myriad pulses is 

a necessary feature of its ability to accurately read a vehicle’s speed. But for the purposes 

of the purely foundational statute bearing only on admissibility rather than scientific 

certainty, the district court acts within its discretion by reasonably assuming that a properly 

functioning laser unit that accurately applies time, distance, and speed in its calculations to 

a stationary object continues to apply those same elements accurately in its speed 

calculation of a moving object. Put another way, just as we liberally but reasonably 

presume under the statute that a radar unit that accurately calculates sound frequency will 

accurately calculate a car’s speed, Bogren, 410 N.W.2d at 385, and that a radar unit that 

accurately calculates a car’s speed in stationary mode will accurately calculate a car’s speed 

in moving mode, Pulos, 406 N.W.2d at 76, the statute allows the district court to presume 

that a laser unit that accurately measures time when it calculates an object’s distance will 

also accurately measure time when it calculates a car’s speed. We expressly declined to 

require a moving-object laser test in Ali, and Olson’s scientific argument does not call that 

holding into question. 

We reject Olson’s argument that Officer Zabee’s external test failed to measure time 

and that it therefore failed to meet the statutory admissibility requirements. 

D E C I S I O N

The officer’s external distance check established that the laser device was accurately 

measuring distance, and this necessarily indicated that the device was also accurately 

measuring time and speed. The district court did not err by holding that the distance check 

satisfied the requirements of section 169.14, subdivision 10(a)(4), and it did not abuse its 
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discretion by allowing the officer to testify that the laser device measured Olson’s speed at 

70 miles per hour.

Affirmed.