 1       IN THE COURT OF APPEALS OF THE STATE OF NEW MEXICO

 2 Opinion Number:_______________

 3 Filing Date: OCTOBER 22, 2018

 4 NO. A-1-CA-35424

 5 STATE OF NEW MEXICO,

 6         Plaintiff-Appellant,

 7 v.

 8 EMILY A. RUFFIN,

 9         Defendant-Appellee.

10 APPEAL FROM THE DISTRICT COURT OF BERNALILLO COUNTY
11 Jacqueline D. Flores, District Judge

12   Hector H. Balderas, Attorney General
13   Santa Fe, NM
14   Laurie Blevins, Assistant Attorney General
15   Albuquerque, NM

16 for Appellant

17   Dan Cron Law Firm, P.C.
18   Kitren Fischer
19   Dan Cron
20   Santa Fe, NM

21 for Appellee
 1                                      OPINION

 2 HANISEE, Judge.

 3   {1}   The State appeals the district court’s pretrial ruling prohibiting one of its

 4 witnesses from testifying as an expert. We affirm in part, reverse in part, and

 5 remand for further proceedings.

 6 I.      BACKGROUND

 7   {2}   At approximately 7:30 p.m. on October 18, 2013, Deputy Leonard Armijo

 8 responded to a report of a two-vehicle accident involving a Ford Bronco and

 9 Toyota 4Runner. Upon arriving at the scene, Deputy Armijo observed a Ford

10 Bronco lying on its side with a deceased individual inside. Defendant Emily A.

11 Ruffin was standing in front of the Ford Bronco and told Deputy Armijo she was

12 the driver of the Toyota 4Runner. She was in a hurry to pick up a friend from the

13 airport when her phone rang and fell to the floor. When she looked at the floor, the

14 Ford Bronco “swerved and cut in front of her, which had caused the crash.”

15 Deputy Armijo detected an odor of alcohol while talking with Defendant,

16 prompting him to call a DWI unit to his location. Deputy Johan Jareño responded

17 and after investigating Defendant for DWI, placed her under arrest. Defendant was

18 charged, inter alia, with homicide by vehicle and driving while under the influence

19 of intoxicating liquor or drugs.
 1   {3}   A week before trial was scheduled, the State, for the first time, notified the

 2 district court and defense counsel that it intended to qualify Deputy Armijo as an

 3 expert witness in, as the State later clarified, “crash investigations.” The district

 4 court neither ruled on the admissibility of Deputy Armijo’s proposed expert

 5 testimony, nor accepted Deputy Armijo as an expert witness under Rule 11-702

 6 NMRA (providing the requirements for a witness to be qualified and give an

 7 opinion as an expert).

 8   {4}   Four days before trial was scheduled, Defendant filed a motion in limine,

 9 seeking to prohibit Deputy Armijo from testifying as an expert witness on the issue

10 of causation and in regard to accident reconstruction, and to limit his testimony to

11 only his personal observations during his investigation of the accident scene.

12 During the hearing on Defendant’s motion, held the day before trial was scheduled,

13 Defendant also argued that Deputy Armijo’s proposed expert testimony should

14 also be excluded under Rule 11-403 NMRA because it bore “a legitimate risk of

15 misleading the jury.”

16   {5}   During the hearing, Deputy Armijo testified that for approximately eight

17 years he had been assigned to the DWI Traffic Unit of the Bernalillo County

18 Sheriff’s Department. In conjunction with his assignment, he attended a 240-hour,

19 three-phase training course in crash investigations and reconstruction. As part of

20 the first phase of training—“at-scene crash investigations”—Deputy Armijo

                                              2
 1 learned how to respond to crash investigations, assist at and protect the scene, and

 2 observe points of impact, “skid marks,” “yaw marks,” “other debris deposited on

 3 the asphalt,” and vehicles at their “final rest.” During the second phase of

 4 training—“advanced at-scene crash”—he learned “airborne equations, what

 5 vehicles would become airborne[,] . . . speed analysis, crash analysis, [and] what

 6 causes vehicles to change directions.” Deputy Armijo testified that to conduct a

 7 speed analysis, “[y]ou have to ascertain what’s called the coefficient of friction or

 8 what is commonly referred to as the drag factor of the roadway[,]” which is

 9 determined by using a mathematical equation. During the third and final phase of

10 training—“crash reconstruction”—Deputy Armijo learned how to reconstruct a

11 crash, which involves observing the scene, looking at the crash damage, looking at

12 the position of the vehicles, and looking for “any road evidence to include skid

13 marks, [and] vehicle debris[.]” He testified this “teaches you where to locate the

14 area of impact, where the crash occurred, how it occurred, and how the vehicles

15 sustained the damage that they’ve sustained.”

16   {6}   Deputy Armijo explained that while a sergeant can override his

17 recommendation as to whether a full accident reconstruction should be conducted,

18 he only conducts such a reconstruction when there are no independent witnesses,

19 he has no corroborating statements from the drivers, and/or the evidence does not

20 match with what he observes at the scene of the accident. Deputy Armijo testified

                                             3
 1 that, without conducting a full reconstruction of a given accident, he is only able to

 2 form an opinion regarding:

 3         [H]ow the vehicles came together. What contacted. What is on each of
 4         the vehicles. There’s specific damage to each of the vehicles that the
 5         vehicles will sustain during the contact of the vehicles. It’s basically
 6         like a jigsaw puzzle. You can put those two vehicles together. As long
 7         as the damage matches up to what the evidence shows, reconstruction
 8         wouldn’t be necessary.

 9 Deputy Armijo testified that he had investigated over five thousand crashes—three

10 hundred eighty-seven of which involved great bodily injury or fatality—and

11 performed full accident reconstructions in only eleven cases. During ensuing court

12 proceedings, he had been qualified as an expert in “crash investigations” on four

13 prior occasions, and in “crash reconstruction” on six occasions.

14   {7}   In this case, Deputy Armijo decided not to conduct a full accident

15 reconstruction “because what I was looking at, it was quite obvious, it was quite a

16 simple crash.” Deputy Armijo observed “specific damage” to the Ford Bronco’s

17 red tail light lens, as well as to the clear head light lens of Defendant’s vehicle. He

18 then “walked” the scene of the accident and located pieces of the vehicles’ red and

19 clear lenses deposited on the road approximately seven or eight hundred feet from

20 the vehicles’ resting points, which helped him locate the apparent point of impact.

21 Although he did not see any “braking marks on either vehicle[,]” Deputy Armijo

22 observed yaw marks, which he stated are consistent with a vehicle sliding


                                              4
 1 sideways, and gouge marks, which he explained indicate a vehicle’s roof and/or

 2 metal making contact with the road.

 3   {8}   While discussing the Ford Bronco, Deputy Armijo stated it was “fairly

 4 obvious” that it had rolled over. When asked what starts a rollover, Deputy Armijo

 5 stated:

 6         The stability of that vehicle has been compromised by another vehicle
 7         coming into contact with it. Once that vehicle has gone into the yaw
 8         marks sliding sideways, it’s inevitable that vehicle is going to roll
 9         over due to the fact that the make and model of that vehicle, the
10         speeds, and once the rims come in contact with the
11         pavement[,] . . . [i]t’s going to roll.

12 In addition to not undertaking a full accident reconstruction, Deputy Armijo did

13 not use any mathematical formulae in conjunction with his observations and

14 determinations regarding the accident scene, including those that would be

15 necessary to ascertain vehicle speed.

16   {9}   On cross examination, defense counsel asked Deputy Armijo about

17 Defendant’s Exhibit A, Deputy Armijo’s handwritten field notes concerning the

18 accident. Deputy Armijo admitted that he did not write speed calculations, rollover

19 sequence calculations, or any other type of calculations in his field notes. He also

20 admitted that he “did not perform a timeline analysis of what occurred at various

21 points in the crash,” take crash measurements, analyze scratch patterns on the Ford

22 Bronco to determine how many times it rolled, measure the “distance in the roll

23 sequence,” nor return to the scene of the accident during “daylight hours[.]”
                                            5
 1 Deputy Armijo conceded he did not analyze data from the crash data recorder, and

 2 did not collect or take any daytime photographs of the “roadway fragments.”

 3 Finally, defense counsel presented Deputy Armijo with Exhibit B, the diagram of

 4 the accident created by another officer on the scene, Deputy Phil Gonzales. Deputy

 5 Armijo was unable to say whether Deputy Gonzales documented the “beginning

 6 and end of the roll sequence” or the location of the yaw marks.

 7   {10}   Following testimony, the State explained it planned to present Deputy

 8 Armijo’s expert opinion as to the cause of the crash and that, based on the yaw and

 9 gouge marks on the road and damage to the Ford Bronco, the Ford Bronco had

10 rolled over. The district court first expressed its general skepticism with qualifying

11 investigatory law enforcement officers as expert witnesses because they “sort of

12 have a stake in the outcome.” It then expressed its more specific concern that

13 Deputy Armijo was unable to articulate a methodology “to render an opinion that

14 would be reliable to the jury[,]” and that his opinion would therefore be “more

15 confusing to the jury than helpful.” Although the State argued that Deputy

16 Armijo’s testimony would not be based on scientific evidence, but rather his

17 training, skill, and knowledge, the district court ruled that Deputy Armijo would

18 not be qualified as an expert witness under Rule 11-702. While the district court

19 recognized that Deputy Armijo “had extra training” and that the issue of causation

20 was “key in this case,” it nonetheless ruled that it was prohibiting Deputy Armijo

                                             6
 1 from testifying as to “any conclusions” he reached regarding the cause of the

 2 accident. The district court ruled that Deputy Armijo could only testify about his

 3 personal observations.

 4   {11}   The State appealed the district court’s ruling to this Court under NMSA

 5 1978, Section 39-3-3(B)(2) (1972), before a jury was impaneled, certifying “that

 6 this appeal is not taken for the purpose of delay, and the evidence is a substantial

 7 proof of a fact material to the proceeding.” On appeal, the State elaborates that, if

 8 qualified as an expert, Deputy Armijo would have testified based on his training

 9 and experience, opined “that Defendant’s rear-ending [of] the vehicle traveling in

10 front of her caused the collision[,]” educated the jury about yaw and gouge marks,

11 and testified that he could “match the damage up” from the two vehicles based on

12 the specific damage sustained by both vehicles. Furthermore, Deputy Armijo

13 would testify that, in rear-ending the Ford Bronco, Defendant’s vehicle “caus[ed] it

14 to swerve sideways, then roll an unknown number of times, a theory buttressed by

15 the physical damage to the [Ford] Bronco’s roof support pillars and roof.”

16 II.      DISCUSSION

17   {12}   Appealing the district court’s ruling, the State argues that (1) its appeal is

18 permitted under Section 39-3-3(B)(2); (2) the district court erred in prohibiting

19 Deputy Armijo from testifying as to any of the conclusions he reached as a result

20 of his investigation, including those that could be deemed “lay opinions”; (3) the

                                               7
 1 district court erred in prohibiting Deputy Armijo from testifying as an expert under

 2 Rule 11-702; and (4) the district court erred in excluding Deputy Armijo’s expert

 3 testimony under Rule 11-403. We address each argument in turn.

 4 A.       The State’s Appeal Under Section 39-3-3(B)(2) Is Proper

 5   {13}   Before considering the merits of the State’s appeal, we must first resolve

 6 whether the State had a right, prior to trial, to appeal the district court’s ruling

 7 precluding Deputy Armijo from testifying as an expert witness under Rules 11-702

 8 and 11-403. Under Section 39-3-3(B)(2), the state may appeal a district court’s

 9 order excluding evidence if it “certifies to the district court that the appeal is not

10 taken for purpose of delay and that the evidence is a substantial proof of a fact

11 material in the proceeding.” Defendant does not challenge the State’s appeal on the

12 basis of timeliness, see State v. Mendez, 2009-NMCA-060, ¶ 11, 146 N.M. 409,

13 211 P.3d 206 (concluding that an appeal under Section 39-3-3(B)(2) is timely

14 when initiated before the jury is sworn), rev’d on other grounds by 2010-NMSC-

15 044, 148 N.M. 761, 242 P.3d 328; rather, Defendant argues that the State’s appeal

16 is not proper because the district court’s “ruling did not make it impossible for the

17 State to prove an element of its case” under Section 39-3-3(B)(2).

18   {14}   Substantively, the State’s appeal must concern a court’s suppression or

19 exclusion of evidence that “could constitute substantial proof of a material fact[.]”

20 Mendez, 2010-NMSC-044, ¶ 14. Defendant relies on this Court’s holding in State

                                             8
 1 v. Romero, 2000-NMCA-029, 128 N.M. 806, 999 P.2d 1038, which held that the

 2 State’s appeal was proper under Section 39-3-3(B)(2) because the district court’s

 3 ruling “controlled the course of the presentation of material evidence in the case,

 4 given the [s]tate’s theory.” Romero, 2000-NMCA-029, ¶ 8. We explained that

 5 “[t]he excluded evidence went to the very heart of the proof required to establish

 6 an essential element of the [s]tate’s case . . . [and t]he court’s ruling made it

 7 impossible for the [s]tate to prove an element of its case.” Id. ¶ 9. However, we

 8 later clarified the substantive standard: “[W]e do not read Romero as allowing the

 9 state to appeal only when the district court’s ruling makes it impossible for the

10 state to prove its case. Rather, we interpret Romero as requiring that the excluded

11 evidence be important or significant, as opposed to evidence of minor

12 consequence.” Mendez, 2009-NMCA-060, ¶ 12 (emphasis added). We discuss

13 whether the State’s appeal is proper under the substantive standard as clarified by

14 this Court in Mendez.

15   {15}   When causation is contested in a vehicular homicide case, the state must

16 prove beyond a reasonable doubt that the defendant’s unlawful actions caused the

17 death “in a natural and continuous chain of events[.]” State v. Simpson, 1993-

18 NMSC-073, ¶ 13, 116 N.M. 768, 867 P.2d 1150 (internal quotation marks and

19 citation omitted); see UJI 14-251 NMRA (explaining that when causation is in

20 issue, the state must prove beyond a reasonable doubt that the defendant’s act, “in

                                            9
 1 a natural and continuous chain of events, uninterrupted by an outside event,

 2 resulted in the death and without which the death would not have occurred”). To

 3 prove causation, the State may, but is not required to, call an expert witness. See

 4 State v. Platero, 2017-NMCA-083, ¶ 18, 406 P.3d 557 (concluding that an expert

 5 was not required to prove cause of death in a vehicular homicide case); cf. State v.

 6 Jimenez, 2017-NMCA-039, ¶ 79, 392 P.3d 668 (noting that the state’s decision “to

 7 call or not call a witness is a matter of trial tactics and strategy within the control of

 8 counsel” (internal quotation marks and citation omitted)). Defendant directly

 9 contests the State’s theory that she caused the accident because she was

10 intoxicated, asserting instead that the accident resulted from her momentary

11 inattention when the Ford Bronco moved into her lane. Although Deputy Armijo

12 could offer no opinion regarding whether or not Defendant was intoxicated, the

13 State nonetheless sought to qualify him as an expert who would testify as to the

14 cause of the accident from the standpoint of the sequence of events in which it

15 occurred—a point of apparent dispute which bears upon the element of causation,

16 which the district court identified as “key in this case.” Even Defendant

17 acknowledges that the district court’s ruling prohibited Deputy Armijo from

18 testifying that Defendant caused the accident itself. Under these circumstances, and

19 without the benefit of a developed record regarding the precise nature of the

20 dispute regarding the collision and its aftermath, we have no basis to conclude that

                                               10
 1 the circumstances of an accident are not “important or significant” to a jury’s

 2 determination regarding the element of causation. See Mendez, 2009-NMCA-060,

 3 ¶ 12. As such, the district court’s ruling adversely impacted the State’s capacity to

 4 present evidence that went to the “heart of the proof required to establish the

 5 element” of causation. Id. (internal quotation marks and citation omitted); cf. State

 6 v. Gonzales, 2012-NMCA-034, ¶ 5, 274 P.3d 151 (noting that an expert opinion is

 7 evidence). We conclude in this circumstance that, under Section 39-3-3(B)(2), the

 8 State may, pretrial, appeal from the deprivation of its capacity to prove the element

 9 of causation by means of an expert witness. We therefore proceed to the merits of

10 the State’s appeal.

11 B.       Deputy Armijo’s “Lay Conclusions”

12   {16}   The State first argues that by prohibiting Deputy Armijo from testifying as

13 to “any conclusions” he reached regarding the circumstances of the accident, the

14 district court impermissibly prohibited him from offering certain conclusions that

15 even a layperson would be permitted to offer at trial. As an example, the State cites

16 State v. Wildgrube, 2003-NMCA-108, 134 N.M. 262, 75 P.3d 862, where this

17 Court held that a law enforcement officer who had observed the scene of the

18 accident was permitted to testify as a lay witness under Rule 11-701 NMRA about

19 the location of the debris and to offer an opinion about the point of impact through

20 a diagram. Wildgrube, 2003-NMCA-108, ¶ 15. Wildgrube involved the officer

                                             11
 1 inputting measurements he had taken at the scene of the accident into a computer

 2 program which then produced a diagram of the scene. Id. ¶ 12. The officer then

 3 testified, without objection, as to the evidence he collected, the methods he used to

 4 gather the evidence, the methods he used to measure the location of debris found at

 5 the scene, the methods he used to create the computer-generated diagram, and his

 6 opinions about the diagram’s accuracy and “the meaning of the debris path.” Id.

 7 ¶¶ 12-13.

 8   {17}   In this case, however, the State planned to offer Deputy Armijo’s testimony

 9 to not only his personal observations, but also to explain his conclusions regarding

10 what those observations mean and opine as to the cause of the accident in light of

11 his specialized training and experience. And, unlike in Wildgrube, Defendant

12 objected to the proposed testimony. The State argued to the district court that

13 Deputy Armijo’s opinion in this case and general understanding of traffic

14 investigations, yaw marks, speed calculations, and crash data analysis were a

15 product of his specialized training and experience not possessed by a regular police

16 officer. Despite its similarity to the accident scene evaluation undertaken in

17 Wildgrube, we conclude that the testimony excluded by the district court was, in

18 this circumstance, expert testimony. See State v. Winters, 2015-NMCA-050, ¶ 11,

19 349 P.3d 524 (noting that “opinion testimony of lay witnesses is generally confined

20 to matters which are within the common knowledge and experience of an average

                                             12
 1 person” (internal quotation marks and citation omitted)); cf. State v. Vargas, 2016-

 2 NMCA-038, ¶¶ 22-23, 368 P.3d 1232 (concluding that an officer’s testimony about

 3 the technical properties of stun guns and identifying stun gun injuries was based on

 4 his law enforcement training and experience, and was therefore expert testimony).

 5 We accordingly hold that the delineation of lay versus expert testimony in this

 6 instance is not controlled by Wildgrube and we have no basis on the limited record

 7 before us to reverse the district court’s conclusion that Deputy Armijo’s proposed

 8 testimony was not lay opinion testimony.

 9 C.       Deputy Armijo’s Expert Testimony

10   {18}   Having concluded that the district court excluded conclusions reached by

11 Deputy Armijo that constitute expert testimony, we next address whether it erred in

12 doing so. Our analysis begins with Rule 11-702, which provides that “[a] witness

13 who is qualified as an expert by knowledge, skill, experience, training, or

14 education may testify in the form of an opinion or otherwise if the expert’s

15 scientific, technical, or other specialized knowledge will help the trier of fact to

16 understand the evidence or to determine a fact in issue.” A witness may be

17 admitted as an expert under Rule 11-702 upon the satisfaction of three

18 requirements: (1) “that the expert be qualified”; (2) that the testimony “will assist

19 the trier of fact”; and (3) that the expert’s testimony concern “scientific, technical

20 or other specialized knowledge.” State v. Alberico, 1993-NMSC-047, ¶¶ 43-45,

                                             13
 1 116 N.M. 156, 861 P.2d 192 (internal quotation marks omitted). “[T]he admission

 2 of expert testimony . . . is peculiarly within the sound discretion of the [district]

 3 court and will not be reversed absent a showing of abuse of that discretion.” Id.

 4 ¶ 58. Although Defendant argues that the district court’s exclusion of Deputy

 5 Armijo’s expert testimony was proper because Deputy Armijo was not sufficiently

 6 qualified, the district court did not exclude his expert testimony on that ground.

 7 Rather, the district court ruled that the proposed expert testimony lacked a reliable

 8 methodology, a ruling that implicates the scientific knowledge element of the third

 9 requirement for the admission of expert testimony. See Andrews v. U.S. Steel

10 Corp., 2011-NMCA-032, ¶¶ 12-13, 149 N.M. 461, 250 P.3d 887 (holding that,

11 under Alberico, and Daubert v. Merrell Dow Pharmaceuticals, Inc., 509 U.S. 579

12 (1993), “the proponent of [scientific expert] testimony must establish the reliability

13 of the science and methodology on which it is based” to satisfy the third

14 requirement for expert testimony). We therefore limit our discussion of the district

15 court’s ruling to its stated basis for exclusion under Rule 11-702. See Rule 12-

16 321(A) NMRA (“To preserve an issue for review, it must appear that a ruling or

17 decision by the trial court was fairly invoked.”).

18   {19}   “Where expert testimony concerns scientific knowledge, the proponent of

19 the testimony must establish the reliability of the science and methodology on

20 which it is based.” Andrews, 2011-NMCA-032, ¶ 13. When determining the

                                             14
 1 admissibility of expert testimony involving scientific knowledge, the district court

 2 should, pursuant to Alberico and Daubert, consider whether the testimony is

 3 “grounded in valid, objective science and [is] reliable enough to prove what it

 4 purports to prove” by testing the expert’s methodology. State v. Torrez, 2009-

 5 NMSC-029, ¶ 21, 146 N.M. 331, 210 P.3d 228 (internal quotation marks and

 6 citation omitted). The Alberico-Daubert standard applies only to scientific expert

 7 testimony. See State v. Torres, 1999-NMSC-010, ¶ 43, 127 N.M. 20, 976 P.2d 20

 8 (concluding that “the Alberico-[D]aubert standard applies only to expert testimony

 9 that relies on scientific knowledge,” rather than all forms of expert testimony); see

10 also Quintana v. Acosta, 2014-NMCA-015, ¶ 14, 316 P.3d 912 (noting that the

11 Alberico-Daubert standard applies “only when the district court is evaluating the

12 admissibility of scientific testimony”). “[T]he initial determination of whether to

13 apply the Alberico-Daubert standard entails a conclusion of law that is subject to

14 de novo review.” Torres, 1999-NMSC-010, ¶ 28.

15   {20}   Thus, we first answer whether Deputy Armijo’s expert testimony was based

16 on “scientific” knowledge, thereby requiring application of the heightened

17 Alberico-Daubert standard. “Evidence is based on scientific knowledge if it is not

18 self-explanatory, or if it is based on a scientific or medical principle.” State v.

19 Aleman, 2008-NMCA-137, ¶ 6, 145 N.M. 79, 194 P.3d 110 (internal quotation

20 marks and citation omitted); see State v. Bregar, 2017-NMCA-028, ¶¶ 32-33, 390

                                            15
 1 P.3d 212 (noting that expert testimony involving the use of physics equations is

 2 based on scientific knowledge); cf. State v. Brown, 687 P.2d 751, 754 (Or. 1984)

 3 (en banc) (“The term ‘scientific’ . . . refers to evidence that draws its convincing

 4 force from some principle of science, mathematics and the like.”). We understand

 5 Deputy Armijo’s proposed expert testimony to fall within two distinct categories:

 6 non-scientific and scientific expert testimony.

 7 1.       Deputy Armijo’s Non-Scientific Expert Testimony

 8   {21}   To better frame the narrow scope of Deputy Armijo’s scientific expert

 9 testimony, we begin by identifying Deputy Armijo’s non-scientific expert

10 testimony. As Deputy Armijo testified at the Alberico hearing, he was able to

11 match “specific damage” to the Ford Bronco’s red tail light lens and the Toyota

12 4Runner’s clear front lens, which led him to conclude that the front of the Toyota

13 4Runner made contact with the rear of the Ford Bronco. He also located the Ford

14 Bronco’s red lens and the Toyota 4Runner’s clear lens approximately seven or

15 eight hundred feet from the vehicles, allowing him to conclude that the Toyota

16 4Runner and the Ford Bronco collided where the lenses were discovered. He

17 planned to inform the jury about the yaw and gouge marks he observed and the

18 phenomena those marks generally indicate. Finally, based on the yaw and gouge

19 marks found on the road and the physical damage to the Ford Bronco, Deputy

20 Armijo concluded and the State proposed that he testify that the Ford Bronco rolled

                                            16
 1 over. Deputy Armjio’s non-scientific expert testimony is based on his personal

 2 observations of physical evidence found at the scene, is straightforward, and

 3 appears to fit directly within the scope of his specialized training. Moreover, none

 4 of these points of testimony arose from application of scientific principles or

 5 mathematic computations. We therefore conclude that this testimony was not based

 6 on “scientific knowledge” and the district court erred in applying the Alberico-

 7 Daubert standard to this testimony.

 8   {22}   Having concluded that the district court applied the wrong legal standard, we

 9 also analyze whether the district court abused its discretion in denying the

10 admission of Deputy Armijo’s non-scientific expert testimony. A district court

11 “abuses its discretion when it exercises its discretion based on a misunderstanding

12 of the law.” State v. Lente, 2005-NMCA-111, ¶ 3, 138 N.M. 312, 119 P.3d 737.

13 Given the district court’s application of the wrong legal standard to Deputy

14 Armijo’s non-scientific expert testimony, we conclude it abused its discretion in

15 this respect.

16   {23}   Our holding in this regard should not, however, be construed to command

17 that the district court determine Deputy Armijo’s non-scientific expert testimony to

18 be either reliable or unreliable. See Torrez, 2009-NMSC-029, ¶ 21 (holding that

19 “even with non-scientific expert testimony, the [district] court must exercise its

20 gate-keeping function and ensure that the expert’s testimony is reliable”). When

                                              17
 1 ruling on the admissibility of non-scientific expert testimony, the district court

 2 “must evaluate a non-scientific expert’s personal knowledge and experience to

 3 determine whether the expert’s conclusions on a given subject may be trusted.” Id.

 4 The district court tests “whether an expert’s skills, experience, training, or

 5 education qualify him or her in the relevant subject . . . [and] uses these same

 6 factors . . . to test the validity of the expert’s conclusions . . . [and determine

 7 whether they] prove what they purport to prove.” Id. ¶ 22. Whereas the district

 8 court misapplied the Alberico-Daubert standard to test the reliability of Deputy

 9 Armijo’s methodology in the first instance, on remand it should instead test the

10 validity of Deputy Armijo’s non-scientific expert testimony by evaluating whether

11 his conclusions are consistent with his specialized training and experience. If

12 answered affirmatively, Deputy Armijo’s non-scientific testimony would be

13 admissible under Rule 11-702.

14 2.       Deputy Armijo’s Scientific Expert Testimony

15   {24}   We next discuss what we conclude to be Deputy Armijo’s scientific expert

16 testimony regarding the cause of the apparent rollover. As this Court noted in

17 Bregar, expert testimony is scientific when it applies physics principles. 2017-

18 NMCA-028, ¶¶ 32-33. Defendant contends that Deputy Armijo planned to

19 “testif[y] to scientific matters involving math and physics.” We agree. Whereas his

20 expert opinion that a rollover occurred is based on his non-scientific knowledge,

                                           18
 1 his expert opinion regarding the cause of the apparent rollover—in other words,

 2 why it happened vis-à-vis the colliding of the two impacted vehicles—necessarily

 3 requires that he analyze the chain of events leading up to, and culminating in the

 4 Ford Bronco rolling over. But by Deputy Armijo’s own admission, determining

 5 how a rollover starts requires analyzing, amongst other things, the vehicles’

 6 speeds. Deputy Armijo testified that analyzing speed requires the use of a

 7 mathematical equation to “ascertain what’s called the coefficient of friction or

 8 what is commonly referred to as the drag factor of the roadway.” Accordingly,

 9 pursuant to Deputy Armijo’s own description of the methodology needed to

10 identify the cause of a collision that results in a vehicle rollover, any expert

11 testimony concerning the cause of this apparent rollover would require application

12 of mathematical principles and would therefore be scientific expert testimony.

13   {25}   The State, however, argues that no scientific expertise was required for this

14 testimony. To support its argument, the State cites Duran v. Lovato in which this

15 Court held that the district court did not abuse its discretion in admitting an

16 officer’s expert testimony about the “area of impact” in an accident involving a

17 pedestrian and vehicle, and whether speed was a factor in the accident. 1982-

18 NMCA-182, ¶¶ 18-19, 99 N.M. 242, 656 P.2d 905 (internal quotation marks

19 omitted). However, Duran was decided prior to both Daubert and Alberico and

20 provides no guidance to this Court about distinguishing between scientific and

                                              19
 1 non-scientific expert testimony. Furthermore, to the extent that Duran remains

 2 good law after Daubert and Alberico, it is factually distinguishable from the

 3 present case. In Duran, the officer took measurements at the scene of the accident

 4 which he later used to create a diagram of the accident scene and relied partly on

 5 his diagram to render his expert opinion. 1982-NMCA-182, ¶ 18. Deputy Armijo

 6 did no such thing. We therefore decline to extend Duran’s rationale to the present

 7 case.

 8   {26}   The State also argues that Deputy Armijo’s testimony was not subject to the

 9 Alberico-Daubert standard because it was based on his specialized knowledge,

10 citing State v. Bullcoming, 2010-NMSC-007, 147 N.M. 487, 226 P.3d 1

11 (Bullcoming II), rev’d on other grounds sub nom. by Bullcoming v. New Mexico,

12 564 U.S. 647 (2011) (Bullcoming III), and State v. Bullcoming, 2008-NMCA-097,

13 144 N.M. 546, 189 P.3d 679 (Bullcoming I). In Bullcoming I, this Court first held

14 that an officer who made contact with a defendant after an accident could testify

15 based on his specialized knowledge that the defendant caused an accident because

16 he “was under the influence of some kind of intoxicating liquor.” 2008-NMCA-

17 097, ¶¶ 10-11 (internal quotation marks omitted); see Bullcoming II, 2010-NMSC-

18 007, ¶ 27 (noting that the record indicated that the officer based his opinion on his

19 contact with the defendant). Our Supreme Court later held that the district court did

20 not abuse its discretion in permitting the officer’s testimony because he was well-

                                             20
 1 qualified and “[d]efense counsel did not conduct voir dire examination or

 2 otherwise challenge his qualifications.” Bullcoming II, 2010-NMSC-007, ¶ 29.

 3 However, both cases are factually distinguishable from this case. In Bullcoming II,

 4 the officer reached his conclusion based on his observations that the defendant

 5 exhibited signs of intoxication and had an odor of alcohol. Id. ¶¶ 4, 27. Here,

 6 considered in sum, Deputy Armijo’s testimony conceded that he needed to apply

 7 physics principles to discover the cause of rollovers.

 8   {27}   Lastly, the State argues that no mathematical modeling was required for

 9 Deputy Armijo’s expert opinion regarding the cause of the apparent rollover, citing

10 Lopez-Juarez v. Kelly, 348 S.W.3d 10 (Tex. Ct. App. 2011). In Lopez-Juarez, the

11 Texas Court of Appeals held that, “[i]n simple accidents, the accident

12 reconstruction can be conducted without mathematical modeling.” Id. at 21.

13 However, the court noted that it was presented with a multiple vehicle accident,

14 differing witness accounts of the accident, and the need to use complex physics

15 calculations to determine fault. Id. at 19 n.13. It therefore concluded that the

16 accident was “complex” which required mathematical modeling. Id. at 22.

17 Although the case before this Court lacked the multivehicle complexity identified

18 by Lopez-Juarez as a basis for requiring a scientific level of expertise, the collision

19 lends itself to two differing interpretations: (1) Defendant’s contention that the

20 accident was caused by a combination of her inattention and the Ford Bronco

                                             21
 1 traveling from its own lane into hers; and (2) Deputy Armijo’s proposed

 2 conclusion that based on the tail and head light lenses deposited on the road, the

 3 yaw and gouge marks discovered on the road, and the damage to the Ford Bronco,

 4 Defendant rear-ended the Ford Bronco, causing the rollover and the driver’s death.

 5 As stated above, the methodology described by Deputy Armijo indicated his need

 6 to apply physics principles and mathematical calculations to determine whether his

 7 suspected conclusion regarding the rollover was supported by scientific

 8 methodology. In other words, Deputy Armijo’s specialized knowledge is no

 9 substitute for scientific methodology when expert testimony is of a scientific nature

10 or depends upon the application of scientific principles. Cf. Aleman, 2008-NMCA-

11 137, ¶ 6 (requiring application of the heightened Alberico-Daubert standard to

12 evidence based on scientific knowledge, i.e., knowledge that is not self-

13 explanatory or is based on scientific or medical principles).

14   {28}   For the aforementioned reasons, we conclude that application of Duran,

15 Bullcoming, and Lopez-Juarez is inapposite here, and that Deputy Armijo’s expert

16 testimony regarding the cause of the apparent rollover in this case is based on

17 scientific knowledge and must be subjected to the heightened Alberico-Daubert

18 standard. See Daubert, 509 U.S. at 590 (holding that “in order to qualify as

19 ‘scientific knowledge,’ an inference or assertion must be derived by the scientific

20 method”). But here, Deputy Armijo elected not to conduct a full reconstruction,

                                             22
 1 apply mathematical formulae, or engage in other procedures consistent with a final

 2 determination of what happened and why. Deputy Armijo neither testified to, nor

 3 documented, any discernible methodology from which the district court could test

 4 the reliability of his opinion. Reiterating that our Supreme Court has given the

 5 district court broad discretion in the exclusion of expert testimony, we conclude

 6 that the district court’s exclusion of Deputy Armijo’s proposed expert testimony

 7 regarding the cause of the rollover was not an abuse of its discretion in light of the

 8 facts of his investigation in this case. See State v. Downey, 2008-NMSC-061, ¶ 30,

 9 145 N.M. 232, 195 P.3d 1244 (explaining that “for scientific evidence to be

10 admissible under Rule 11-702, the reasoning or methodology underlying the

11 testimony must not only be scientifically valid, it also must be properly applied to

12 the facts in [the] issue” (alteration, omission, internal quotation marks, and citation

13 omitted); Alberico, 1993-NMSC-047, ¶ 58 (holding that the exclusion of expert

14 testimony is within the sound discretion of the district court and will not be

15 disturbed unless “manifestly erroneous” (internal quotation marks and citation

16 omitted)).

17 D.       Rule 11-403

18   {29}   Having concluded that Deputy Armijo’s non-scientific expert testimony still

19 has the potential on remand to pass muster under Rule 11-702, we also discuss the

20 district court’s ruling that it was nonetheless excludable under Rule 11-403. Even

                                             23
 1 if expert testimony is admissible under Rule 11-702, it must be relevant under Rule

 2 11-401 NMRA and even if relevant, may be excluded under Rule 11-403.

 3 Alberico, 1993-NMSC-047. ¶ 55. Evidence is relevant if “it has any tendency to

 4 make a fact more or less probable than it would be without the evidence” and it is

 5 “of consequence in determining the action.” Rule 11-401. Relevant evidence,

 6 although admissible under Rule 11-401, may still be excluded “if its probative

 7 value is substantially outweighed by a danger of . . . unfair prejudice . . . [or]

 8 misleading the jury[.]” Rule 11-403. “Unfair prejudice does not mean the damage

 9 to a defendant’s case that results from the legitimate probative force of the

10 evidence; rather it refers to evidence that tends to suggest decision on an improper

11 basis.” State v. Anderson, 1994-NMSC-089, ¶ 63, 118 N.M. 284, 881 P.2d 29. The

12 district court’s exclusion of evidence under Rule 11-403 is reviewed for an abuse

13 of discretion. State v. Chamberlain, 1991-NMSC-094, ¶ 9, 112 N.M. 723, 819 P.2d

14 673.

15   {30}   The probative value of Deputy Armijo’s testimony is high because it bears

16 directly upon whether Defendant rear-ended the Ford Bronco and caused the

17 accident, which is a key issue in this case. Although the district court did not

18 explicitly cite Rule 11-403 in its ruling, Defendant argued that the expert testimony

19 would impermissibly mislead the jury under Rule 11-403 and the district court

20 considered whether the evidence was relevant and weighed its probative value

                                            24
 1 against two concerns. We therefore review its exclusion of Deputy Armijo’s expert

 2 testimony under Rule 11-403. See Progressive Cas. Ins. Co. v. Vigil, 2018-NMSC-

 3 014, ¶ 12, 413 P.3d 850 (concluding that an appellate court may review a district

 4 court’s exclusion of evidence under Rule 11-403 when the district court fails to cite

 5 the rule but the record reflects that the parties’ arguments and the district court’s

 6 ruling were guided by the rule’s principles). First, the district court noted its

 7 skepticism about permitting investigating officers to testify as experts in their own

 8 cases as they “have a stake in the outcome.” Second, the district court stated that it

 9 was concerned that Deputy Armijo’s testimony would be confusing to the jury

10 because his opinion lacked a scientific basis that would render it reliable.

11   {31}   As to the district court’s first concern, any extent to which Deputy Armijo’s

12 involvement in this case had the potential to impact his testimony is a question of

13 credibility for the jury. See Alberico, 1993-NMSC-047, ¶ 37 (explaining that it is

14 “the most basic function of a jury to arbitrate the weight and credibility of

15 evidence, even expert opinion testimony”); Poore v. State, 1980-NMSC-035, ¶ 5,

16 94 N.M. 172, 608 P.2d 148 (concluding that “the credibility of the witnesses was

17 for the jury to determine”); State v. Paiz, 1999-NMCA-104, ¶ 30, 127 N.M. 776,

18 987 P.2d 1163 (noting that “the jury acts as the sole fact[-]finder based upon its

19 weighing of the evidence and credibility of the witnesses” (emphasis added)).

20 Defendant, however, argues that several issues arise when the State calls an

                                              25
 1 investigating officer to testify as an expert witness. See United States v. Dukagjini,

 2 326 F.3d 45, 51 (2d Cir. 2003). The court in Dukagjini noted that when a case

 3 agent testifies as an expert, “the government confers upon him the aura of special

 4 reliability and trustworthiness surrounding expert testimony.” Id. at 53 (internal

 5 quotation marks and citation omitted). Our Supreme Court has explicitly rejected

 6 this proposition. See Alberico, 1993-NMSC-047, ¶ 36 (concluding that the

 7 “premise that juries are awed by the aura of the infallibility of expert opinion

 8 testimony and thus defer to it is flawed speculation” (internal quotation marks

 9 omitted)).

10   {32}   The court in Dukagjini also noted that “there is an increased danger that the

11 expert testimony will stray from applying reliable methodology and convey to the

12 jury the witness’s sweeping conclusions about [the defendants’] activities[.]”

13 Dukagjini, 326 F.3d at 54 (internal quotation marks and citation omitted).

14 However, the Dukagjini court explained, and we agree, that it is the responsibility

15 of the district court to remain vigilant and ensure that the expert not stray from the

16 scope of his/her expertise. See id. at 54-56 (noting that it is the role of district

17 courts to remain “vigilant gatekeepers” to ensure that the expert witness not

18 deviate “from the strictures of Rule[ 11-]403 and [Rule 11]702”); see also Vargas,

19 2016-NMCA-038, ¶¶ 13, 17 (noting that a witness may provide both lay and expert

20 testimony in a single case, but “[w]hen the line between lay and expert opinion is

                                              26
 1 blurred during the course of a single witness’s testimony, it is the proper function

 2 of the district court, as gatekeeper, to correct the error when raised”). Here, there

 3 was no indication that Deputy Armijo was going to stray from any strictures set

 4 forth by the district court.

 5   {33}   For these reasons, the danger of unfair prejudice or misleading the jury

 6 stemming from Deputy Armijo’s involvement in this case is speculative and

 7 minimal, at best, particularly given the availability of limiting jury instructions. See

 8 State v. King, 2012-NMCA-119, ¶ 5, 291 P.3d 160 (explaining that “[a] district

 9 court abuses its discretion if its decision is obviously erroneous, arbitrary, or

10 unwarranted, or clearly against the logic and effect of the facts and circumstances

11 of the case” (internal quotation marks and citation omitted)); see also UJI 14-118

12 NMRA (“You should consider each expert opinion and the reasons stated for the

13 opinion, giving them such weight as you think they deserve. You may reject an

14 opinion entirely if you conclude that it is unsound.”).

15   {34}   As to the district court’s second concern, as we have concluded above,

16 Deputy Armijo’s non-scientific expert testimony did not require the district court

17 to probe whether he used a reliable methodology. The district court did not

18 consider this distinction. Rather, it found that the lack of a reliable methodology—

19 the standard applied to expert testimony based on scientific knowledge—would

20 confuse the jury. Having considered the distinction between expert testimony

                                              27
 1 based on scientific versus non-scientific knowledge, we conclude that the danger

 2 of unfair prejudice or misleading the jury is slight compared to the evidence’s

 3 probative value. A holding to the contrary would effectively permit the district

 4 court to circumvent our Supreme Court’s explicit restriction of the Alberico-

 5 Daubert standard to expert testimony based on scientific knowledge—a result we

 6 cannot permit. See Torres, 1999-NMSC-010, ¶ 43 (concluding that the Alberico-

 7 Daubert standard applies only to “expert testimony that relies on scientific

 8 knowledge,” rather than all forms of expert testimony); see also Lente, 2005-

 9 NMCA-111, ¶ 3 (noting that a district “court abuses its discretion when it exercises

10 its discretion based on a misunderstanding of the law”). As there is no danger of

11 unfair prejudice or misleading the jury that substantially outweighs the probative

12 value of Deputy Armijo’s expert testimony, we conclude that the district court

13 abused its discretion in excluding this portion of Deputy Armijo’s expert testimony

14 under Rule 11-403.

15 III.     CONCLUSION

16   {35}   We conclude that the State properly appealed to this Court, the district court

17 did not err in excluding Deputy Armijo’s scientific expert testimony, and the

18 district court erred in excluding his non-scientific expert testimony. We therefore

19 affirm in part, reverse in part, and remand for further proceedings consistent with

20 this opinion.

                                              28
1   {36}   IT IS SO ORDERED.


2                                   ______________________________
3                                   J. MILES HANISEE, Judge

4 WE CONCUR:


5 ________________________
6 JULIE J. VARGAS, Judge


7 ________________________
8 EMIL J. KIEHNE, Judge




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