Court Opinion

ID: 4449830
Source: CourtListenerOpinion
Date Created: 2019-10-24 16:02:54.749521+00
Date Added: 2024-06-11T14:46:12.300903
License: Public Domain

The summaries of the Colorado Court of Appeals published opinions
  constitute no part of the opinion of the division but have been prepared by
  the division for the convenience of the reader. The summaries may not be
    cited or relied upon as they are not the official language of the division.
  Any discrepancy between the language in the summary and in the opinion
           should be resolved in favor of the language in the opinion.

                                                                  SUMMARY
                                                            October 24, 2019

                               2019COA160

No. 17CA0495, People v. Shanks — Evidence — Opinions and

Expert Testimony — Testimony by Experts

     In this criminal appeal, a division of the court of appeals

considers whether a trial court must conduct a Shreck hearing

before admitting expert witness testimony analyzing historical cell

site data. As an issue of first impression, but consistent with most

federal courts, the division holds that the use of historical cell site

data to determine the general geographic location of a cell phone is

widely accepted as reliable and does not require a Shreck hearing.

In so holding, the division distinguishes historical cell site analysis

from the theory of granulization, which remains a source of

controversy within the scientific and forensic communities.
Because the evidence offered at trial was within the bounds of

reliable historical cell site data analysis, it was properly admitted.

     The division also rejects the defendant’s contentions that the

district court erred in denying his motion to suppress the victim’s

out-of-court identification and in admitting the victim’s in-court

identification; that the district court violated his rights to due

process, to present a defense, and to a fair trial by disallowing

certain evidence in support of and not instructing the jury on an

alternate suspect defense; and that the district court erred by

allowing reference to his nickname during trial.

     Accordingly, the division affirms the judgment of conviction.
COLORADO COURT OF APPEALS                                          2019COA160

Court of Appeals No. 17CA0495
Jefferson County District Court No. 14CR2888
Honorable Tamara S. Russell, Judge

The People of the State of Colorado,

Plaintiff-Appellee,

v.

Charles Jenson Shanks,

Defendant-Appellant.

                            JUDGMENT AFFIRMED

                                  Division III
                          Opinion by JUDGE BROWN
                       Furman and Davidson*, JJ., concur

                          Announced October 24, 2019

Philip J. Weiser, Attorney General, Jillian J. Price, Senior Assistant Attorney
General, Denver, Colorado, for Plaintiff-Appellee

Lauretta A. Martin Neff, Alternate Defense Counsel, Grand Junction, Colorado,
for Defendant-Appellant

*Sitting by assignment of the Chief Justice under provisions of Colo. Const. art.
VI, § 5(3), and § 24-51-1105, C.R.S. 2019.
¶1    Defendant Charles Jenson Shanks appeals from his conviction

 on two counts of kidnapping, two counts of burglary, and one count

 each of robbery, felony menacing, assault, and false imprisonment.

 He contends that the district court erred by (1) admitting expert

 witness testimony about historical cell site analysis without first

 conducting an evidentiary hearing; (2) admitting an impermissibly

 suggestive out-of-court identification and an in-court identification

 based thereon; (3) excluding his alternate suspect defense; and (4)

 allowing the use of his nickname, “Capone,” at trial. He also

 contends that the cumulative effect of these errors warrants

 reversal. We affirm.

¶2    Addressing an issue of first impression in Colorado, we

 conclude that expert testimony explaining how historic cell site data

 is used to provide a general geographic location of a cell phone at a

 given time may be admitted without first holding an evidentiary

 hearing on the reliability of the methodology.

                           I.   Background

¶3    Shanks and his codefendant, William Cody, were charged with

 numerous offenses arising from the home invasion and assault of

 the victim.

                                    1
¶4    The victim and Cody worked together and occasionally

 socialized outside of work. The victim supplied Cody with

 marijuana and the two men sometimes smoked marijuana together.

 On the night of the charged offenses, Cody called the victim to

 purchase some marijuana and arranged for his “sister,”

 codefendant Arianna Eastman, to pick it up for him.

¶5    The victim met Eastman outside his house for the transaction.

 When he turned to go back inside, a masked man, whom the victim

 later identified as Cody, and another unmasked man followed him

 and forced their way inside. The two assailants searched the

 apartment and beat up the victim before leaving with the victim’s

 equipment for growing marijuana.

¶6    A couple of days after this incident, the victim identified

 Shanks as the second assailant from a photo array. The victim

 identified Shanks again during trial.

¶7    A jury ultimately convicted Shanks as charged. The court

 sentenced him to twenty-eight years in the custody of the

 Department of Corrections.

                                   2
                    II.    Historical Cell Site Analysis

¶8     Shanks contends that the district court erred by admitting

  expert witness testimony analyzing historical cell site data without

  first holding a hearing to determine the reliability of the science

  behind such analysis. We disagree.

                          A.        Standard of Review

¶9     We review the district court’s admission of expert testimony for

  an abuse of discretion and will reverse only when the decision is

  manifestly erroneous. See People v. Rector, 248 P.3d 1196, 1200

  (Colo. 2011). “This deference reflects the superior opportunity of

  the trial judge to assess the competence of the expert and to assess

  whether the expert’s opinion will be helpful to the jury.” Id.

                               B.    Applicable Law

¶ 10   A trial court determines the admissibility of expert testimony

  under CRE 702, which provides as follows:

             If scientific, technical, or other specialized
             knowledge will assist the trier of fact to
             understand the evidence or to determine a fact
             in issue, a witness qualified as an expert by
             knowledge, skill, experience, training, or
             education, may testify thereto in the form of an
             opinion or otherwise.

                                          3
  The inquiry focuses on “the reliability and relevance of the proffered

  evidence and requires a determination as to (1) the reliability of the

  scientific principles, (2) the qualifications of the witness, and (3) the

  usefulness of the testimony to the jury.” People v. Shreck, 22 P.3d

  68, 70 (Colo. 2001); accord People v. Campbell, 2018 COA 5, ¶ 40.

  The court must also evaluate the evidence under CRE 403,

  ensuring that the probative value is not substantially outweighed by

  the danger of unfair prejudice. See Rector, 248 P.3d at 1200;

  Shreck, 22 P.3d at 70.

¶ 11   The court’s inquiry “should be broad in nature and consider

  the totality of the circumstances of each specific case.” Shreck, 22

  P.3d at 77; accord Rector, 248 P.3d at 1200. Although the factors

  set forth in Daubert v. Merrell Dow Pharmaceuticals, Inc., 509 U.S.

  579 (1993), provide helpful guidance, a court need not consider any

  specific set of factors when determining the reliability of the

  proffered evidence. Shreck, 22 P.3d at 78.

¶ 12   Concerns about conflicting opinions or whether a qualified

  expert accurately applied a reliable methodology go to the weight of

  the evidence, not its admissibility. See Campbell, ¶ 42. “Such

  concerns ‘are adequately addressed by vigorous cross-examination,

                                      4
  presentation of contrary evidence, and careful instruction on the

  burden of proof.’” Id. (quoting Estate of Ford v. Eicher, 250 P.3d

  262, 269 (Colo. 2011)).

¶ 13   If a party requests that evidence be subjected to a Shreck

  analysis, the trial court may, in its discretion, hold an evidentiary

  hearing. Id. at ¶ 41. “This discretion comports with the trial court’s

  need to ‘avoid unnecessary reliability proceedings in ordinary cases

  where the reliability of an expert’s methods is properly taken for

  granted, and to require appropriate proceedings in the less usual or

  more complex cases where cause for questioning the expert’s

  reliability arises.’” Rector, 248 P.3d at 1201 (quoting Kumho Tire

  Co. v. Carmichael, 526 U.S. 137, 152 (1999)). A hearing is not

  required if the court “has before it sufficient information to make

  specific findings under CRE 403 and CRE 702 about the reliability

  of the scientific principles involved, the expert’s qualification to

  testify to such matters, the helpfulness to the jury, and potential

  prejudice.” Id.

                       C.    Additional Background

¶ 14   Shanks’s defense was that he was not the second assailant

  and that he was at a family gathering on the other side of town

                                      5
  (about eighteen miles southeast of the victim’s house) at the time of

  the offense. The prosecution intended to disprove this defense by

  introducing evidence from Shanks’s phone records and cell tower

  usage data to show that he was in the general area of the victim’s

  home at the time of the offense. To do so, the prosecution disclosed

  investigator Kathleen Battan as an expert in “Forensic Analysis of

  Cellular Phone Records and Cell Tower Function and Data.”

  Defense counsel objected and requested a Shreck hearing.

¶ 15   In its order denying the hearing request, the district court

  noted that whether a Shreck hearing is required to determine the

  admissibility of historical cell site analysis is a novel issue in

  Colorado. It then reviewed federal case law analyzing the issue

  under Fed. R. Evid. 702, which is similar to Colorado’s rule for our

  purposes, before ruling that

             federal courts have generally required a
             pretrial hearing to determine the admissibility
             of expert testimony purporting to pinpoint the
             location of a defendant using cell phone site
             data, whereas a pretrial hearing has generally
             not been required to determine the
             admissibility of testimony merely purporting to
             place a defendant within the service radius of a
             specific tower at a certain time.

                                      6
  Concluding that the prosecution’s proffered evidence fell into the

  latter category — identifying Shanks’s general location when the

  crime was committed — the district court denied the request for a

  hearing.

¶ 16   Shanks renewed his objection and request for hearing multiple

  times, arguing that Ms. Battan based her opinion on a theory called

  “granulization” and the “scientifically unsupported assumption that

  a cell phone connects to the closest cell tower.” Shanks also

  challenged Ms. Battan’s use of pie shaped sectors rather than ovals

  to demonstrate the cell tower service area. Again, the district court

  denied the request for hearing.

¶ 17   At trial, over Shanks’s objection 1, the district court accepted

  Ms. Battan as an expert and allowed her to testify “about forensic

  analysis of cellphone records . . . and also in a limited fashion about

  . . . cell tower function and data.” The court acknowledged that Ms.

  Battan did not have a background in science or engineering but

  1 Shanks did not object to Ms. Battan’s analysis of cell phone
  records or her mapping or identification of the cell towers used to
  make particular calls. Instead, Shanks objected to Ms. Battan’s
  “analysis of sectors, what sectors mean and general technical
  operations of a cellphone tower.”

                                     7
  concluded she did not need to “know how to design, operate or

  manufacture cell towers” to testify about the cell tower data she

  collects and “what that data tells her about cell tower function.”

¶ 18   Ms. Battan testified to the following:

          • Typically, a cell tower has three sectors, each covering

            approximately 120 degrees of a 360-degree circle around

            the tower. The orientation of the sector (the precise

            direction the sector points) is called the azimuth.

          • Law enforcement has access to a database that includes

            the precise physical location of all cell towers and the

            azimuth of each sector of each tower.

          • Shanks’s cell phone carrier produced records that

            included data about when each call was made or

            received, how long the call lasted, and what specific

            sector of what cell tower was used by the cell phone to

            make or receive the call.

          • She mapped the physical location of the cell towers used

            by Shanks’s carrier using Google Earth; identified the

            towers closest to Shanks’s residence, Cody’s residence,

                                    8
          and the victim’s residence; and noted that there were

          approximately 100 towers in between.

       • Using an FBI computer program, she plotted the cell

          tower and sector used for each relevant call reflected in

          Shanks’s phone records. The sectors associated with

          each call were reflected on the exhibits as 120-degree

          wedges with green lines as the general boundaries of the

          sector and a shaded green area between the lines. The

          lines did not depict distance from the cell tower.

                                                         2

2For reader clarity, we have included a map that was part of a trial
exhibit reflecting how Battan mapped the sectors.

                                  9
          • She cannot state how far away a cell phone is from a

            given cell tower during a call or exactly where a cell

            phone is when it uses a particular tower.

          • Many cell tower coverages overlap and a call typically will

            use the cell tower with the clearest and strongest signal

            even if that tower is not the closest. Which tower a

            phone uses is determined by the carrier based on a

            variety of factors.

¶ 19   With this background, Ms. Battan testified about and

  presented exhibits showing the cell towers and sectors used by

  Shanks’s cell phone to make and receive calls before and after the

  attack on the victim. Between 10:36 a.m. and 4:00 p.m., Shanks’s

  phone connected with towers near his home in Aurora. Between

  4:55 p.m. and 7:39 p.m., Shanks’s phone connected with towers

  moving west along the highways between his home and Cody’s

  home in Lakewood. Between 9:00 p.m. and 10:08 p.m., Shanks’s

  phone made or received six calls by connecting to a west-facing

  sector of a tower situated southeast of the victim’s home in

  Edgewater. At 10:27 p.m. the victim called 911 to report the attack.

                                   10
  At 10:39 p.m., Shanks’s phone again connected with the tower

  nearest Cody’s home.

¶ 20   Ms. Battan performed a similar analysis of cell phone records

  for Cody and Eastman. Collectively, the data revealed several

  communications among Shanks, Cody, Eastman, and the victim

  from 9:04 p.m. to 9:51 p.m., and further communications between

  Shanks’s phone and Eastman’s phone between 10:02 p.m. and

  10:08 p.m. Shanks’s, Cody’s, and Eastman’s phones connected to

  towers near the victim’s home for these communications.

¶ 21   Notably, Ms. Battan did not opine that Shanks or his phone

  was in any specific location at any specific time. Nor did she testify

  regarding the overlap in coverage between two cell towers or to the

  range of any tower with which Shanks’s phone connected the night

  of the incident. She also did not testify to the typical coverage

  range of a tower, instead explaining generally that the range of a

  tower in an urban area like Denver will be much shorter than in a

  rural area like the middle of Kansas because of the concentration

  and availability of towers, heavy usage, and physical interference in

  urban areas. Ms. Battan did say, on cross-examination, that she

  believed it was impossible for Shanks’s phone to be eighteen miles

                                    11
  to the southeast of the tower nearest the victim’s home at the time

  it connected to the west-facing sector of that tower.

¶ 22   To counteract Ms. Battan’s testimony, Shanks offered a

  competing expert, Joseph Kennedy. Over the prosecution’s

  objection, the district court accepted Mr. Kennedy as an expert in

  “radio frequency, which includes cell phone tower operations and

  cell phones.” Mr. Kennedy testified to the following:

          • Many cell tower coverages overlap and a call typically will

            use the cell tower with the best call quality, even if that

            tower is not the closest. Which tower a phone uses is

            determined by the carrier based on a variety of factors.

          • Typically, a cell tower has three sectors pointing in three

            different directions. No sector is precisely 120 degrees.

          • One cannot say a cell phone is near a tower simply

            because it connects to that tower. A cell phone can be

            serviced by and connect with any tower within 21.7

            miles.

¶ 23   Accordingly, Mr. Kennedy opined that Shanks’s cell phone

  could have connected to any tower within a service area of

  approximately twenty-one miles and that Shanks could have been

                                    12
  at a family gathering eighteen miles southeast of the tower nearest

  the victim’s home when his phone pinged that tower. However, on

  cross-examination, Mr. Kennedy conceded the 21.7-mile coverage

  area decreases in urban areas and cell towers in the Denver metro

  area would have a more limited coverage area, possibly one to one

  and a half miles.

¶ 24   Finally, to rebut Mr. Kennedy’s opinions, the prosecution

  offered special agent Scott Eicher, who is a founding member of the

  FBI’s Cellular Analysis Survey Team, as an expert in “historical cell

  site data analysis.” Agent Eicher agreed with Ms. Battan and Mr.

  Kennedy that a cell phone generally selects a tower based on signal

  strength and signal quality. He further testified that, although the

  maximum range of a cell tower may be twenty-one miles, in urban

  areas, the cell towers are placed in close proximity and are designed

  so that the signal does not go past the next tower. In other words,

  even in the Denver suburbs, a cell phone must be within a mile or

  mile and a half of a cell tower to use it. According to Agent Eicher,

  it was not feasible for Shanks’s phone to be eighteen miles away

  from the tower with which it was connecting. Even so, Agent Eicher

                                    13
  admitted that only the general location of a phone can be discerned

  from the tower and sector data, not the phone’s exact location.

                              D.   Analysis

¶ 25    Shanks argues the district court erred in admitting Ms.

  Battan’s and Agent Eicher’s testimony without first holding a

  Shreck hearing because their opinions (1) were based on the faulty

  assumption that a cell phone always connects to the nearest tower;

  and (2) were based on unreliable science and methodology.

   1.   The Opinions Were Not Based on the Faulty Assumption that
            a Cell Phone Always Connects to the Nearest Tower

¶ 26    We reject Shanks’s first argument — that the prosecution’s

  experts’ opinions should not have been admitted because they were

  based on the faulty premise that a cell phone always connects to

  the closest tower — because it is inconsistent with the record.

  During pretrial arguments concerning Shanks’s request for a

  Shreck hearing, the prosecution represented to the district court

  that Ms. Battan would not opine that a cell phone necessarily

  connects to the nearest cell tower. Consistent with that

  representation, neither Ms. Battan nor Agent Eicher so testified at

  trial. Instead, both experts testified that a phone will connect with

                                    14
  the tower emitting the strongest, clearest signal. Neither expert’s

  opinion was based on the alleged faulty premise Shanks identifies.

        2.   The Opinions Were Based on Reliable Methodology

¶ 27   According to Shanks, Ms. Battan’s and Agent Eicher’s

  opinions were based on unreliable science and methodology

  because they relied on a theory called “granulization.” To

  understand Shanks’s argument, it is necessary to provide some

  background on the use of historical cell site data and its general

  acceptance nationwide.

¶ 28   “Historical cell-site analysis uses cell phone records and cell

  tower locations to determine, within some range of error, a cell

  phone’s location at a particular time.” United States v. Hill, 818

  F.3d 289, 295 (7th Cir. 2016) (citing Aaron Blank, The Limitations

  and Admissibility of Using Historical Cellular Site Data to Track the

  Location of A Cellular Phone, 18 Rich. J.L. & Tech. 3, 5 (2011)).

  Essentially, a cell phone is a two-way radio that uses a cellular

  network to communicate. Id. Each cell site or tower has a limited

  geographic range, which depends on the number and height of the

  antennas on the cell site, topography of the surrounding land, and

  natural and manmade obstructions. Id.

                                    15
¶ 29   “In urban areas, cell towers may be located every one-half to

  one mile, while cell sites in rural areas may be three to five miles

  apart.” Id. A cell phone generally connects to the tower with the

  strongest signal, although adjoining towers may provide coverage

  overlap. Id. There are several factors that determine which tower a

  cell phone will connect with, including proximity, geography,

  topography, environmental factors, the technical characteristics of

  the relevant phone, and the number, height, and angle of antennas

  on the tower. See id. at 295-96; State v. Johnson, 797 S.E.2d 557,

  561-62 (W. Va. 2017).

¶ 30   “A cellphone generates ‘historical’ cell-site data when it places

  a call and connects to a specific cell tower.” United States v.

  Reynolds, 626 F. App’x 610, 614-15 (6th Cir. 2015). Phone

  companies maintain call detail records, which include data about

  the duration of the call and the tower and sector to which the cell

  phone connected. See id. at 615; United States v. Jones, 918 F.

  Supp. 2d 1, 5 (D.D.C. 2013); United States v. Eady, No. 2:12-CR-

  00415-DCN-3, 2013 WL 4680527, at *3 (D.S.C. Aug. 30, 2013)

  (unpublished opinion). In addition, the cell service providers

  maintain a list of the precise location of each tower and the

                                    16
  specifications for each of the sectors of the tower. See Jones, 918 F.

  Supp. 2d at 5.

¶ 31   Typically, in criminal cases, the prosecution offers a witness

  who uses these resources to plot on a map the location of the cell

  tower used by an individual’s cell phone for a call or series of calls.

  See, e.g., United States v. Machado-Erazo, 950 F. Supp. 2d 49, 54

  (D.D.C. 2013); Jones, 918 F. Supp. 2d at 4-5; Eady, 2013 WL

  4680527, at *3; United States v. Davis, No. 11-60285-CR, 2013 WL

  2156659, at *5 (S.D. Fla. May 17, 2013) (unpublished opinion).

  Often, these witnesses also will plot the specific sector to which the

  individual’s phone connected by drawing lines coming out from

  each tower at a 120-degree angle. See Machado-Erazo, 950 F.

  Supp. 2d at 54; Jones, 918 F. Supp. 2d at 3; Eady, 2013 WL

  4680527, at *3; Davis, 2013 WL 2156659, at *5. From these maps,

  the witness may opine that the individual’s phone was likely within

  a general geographic location, see Jones, 918 F. Supp. 2d at 5, or

  the coverage area of a particular sector, see Eady, 2013 WL

  4680527, at *3, at the time of each call.

¶ 32   Federal courts “that have been called upon to decide whether

  to admit historical cell-site analysis have almost universally done

                                     17
  so.” Hill, 818 F.3d at 297 (collecting cases); Machado-Erazo, 950 F.

  Supp. 2d at 56 (collecting cases). Several state courts have done

  the same. See, e.g., People v. Fountain, 62 N.E.3d 1107, 1124-25

  (Ill. App. Ct. 2016) (collecting cases). And a number of these courts

  have concluded that the methodology described above is widely

  accepted as reliable and may be admitted without first holding an

  evidentiary hearing. See, e.g., Hill, 818 F.3d at 298; Jones, 918 F.

  Supp. 2d at 4-5; Fountain, 62 N.E.3d at 1124-25; Commonwealth v.

  Nevels, 203 A.3d 229, 241 (Pa. Super. Ct. 2019). In so doing,

  however, these courts have distinguished the use of historic cell site

  data to determine the general location of a phone from the theory of

  “granulization,” which purports to identify a caller’s specific

  location. See United States v. Evans, 892 F. Supp. 2d 949, 956-57

  (N.D. Ill. 2012).

¶ 33   The theory of “granulization” was rejected by the United States

  District Court for the Northern District of Illinois in Evans, on

  which Shanks heavily relies. Although Evans does not define

  “granulization,” the court explained that the theory requires an

  expert to identify

                                    18
             (1) the physical location of the cell sites used
             by the phone during the relevant time period;
             (2) the specific antenna used at each cell site;
             and (3) the direction of the antenna’s coverage.
             He then estimates the range of each antenna’s
             coverage based on the proximity of the tower to
             other towers in the area. This is the area in
             which the cell phone could connect with the
             tower given the angle of the antenna and the
             strength of its signal. Finally, using his
             training and experience, [the expert] predicts
             where the coverage area of one tower will
             overlap with the coverage area of another.

  Id. at 952. Using this theory, the prosecution in Evans sought to

  prove that the defendant was in the same building where the

  kidnapping victim was held for ransom because the building fell

  squarely within the coverage overlap of two towers used by the

  defendant’s phone to make calls during a relevant time period. Id.

¶ 34   The court identified two flaws with the theory of granulization:

  (1) it assumes that a cell phone uses the tower closest to it at the

  time of a call, without accounting for the possibility that the phone

  might have connected to other towers based on a variety of factors;

  and (2) it remains wholly untested by the scientific community. Id.

  at 956. Although the court acknowledged that certain types of

  historical cell site analysis are reliable and admissible, it rejected

                                     19
  the use of granulization theory to pinpoint the defendant’s location.

  Id. at 953, 955, 957.

¶ 35   Having considered the foregoing cases, we hold that the use of

  historical cell site data to determine the general geographic location

  of a cell phone is widely accepted as reliable and does not require a

  Shreck hearing. Accordingly, we conclude the district court did not

  abuse its discretion by denying Shanks’s request for a Shreck

  hearing.

¶ 36   We further conclude that the evidence presented at trial was

  within the bounds of reliable historical cell site analysis. The

  prosecution experts generally explained how cell towers work and

  identified the variables and limitations incorporated into their

  analyses. Ms. Battan mapped the cell towers, identified which of

  Shanks’s calls used which towers and sectors, and opined — when

  asked on cross-examination — that it was not possible for Shanks’s

  phone to be eighteen miles away from a tower to which it

  connected.

¶ 37   Agent Eicher testified that he had reviewed Ms. Battan’s

  analysis and agreed with it. He further opined, based on the

  approximate coverage area of cell towers in the Denver metro area,

                                    20
  that it was not feasible for Shanks’s phone to be eighteen miles

  away at the time of the offense.

¶ 38   Importantly, neither expert opined about coverage overlap

  between towers or that a cell phone necessarily connects to the

  closest tower. Neither expert opined as to the precise location of

  Shanks’s phone at any specific time.

¶ 39   Shanks takes issue with how Ms. Battan portrayed the cell

  tower sectors on her map and how Agent Eicher estimated the

  range of cell towers in the Denver metro area. Shanks also argues

  that the prosecution experts failed to consider the many variables

  affecting how a cell phone and tower connect.

¶ 40   But to the extent either expert’s opinion was based on

  assumptions about coverage range or fails to account for certain

  variables, any challenges to those assumptions or to the expert’s

  application of variables went to the weight of the evidence, not its

  admissibility. See Jones, 918 F. Supp. 2d at 5 (“[T]o the extent that

  Agent Eicher’s testimony relies on assumptions about the strength

  of the signal from a given cell tower, any challenges to those

  assumptions go to the weight of his testimony, not its reliability.”).

  Indeed, while assumptions and variables may be tested by vigorous

                                     21
  cross-examination, they do “not render the fundamental

  methodology of cell site analysis unreliable.” Id.; see also United

  States v. Pembrook, 119 F. Supp. 3d 577, 597-98 (E.D. Mich. 2015)

  (“[T]o the extent that [the witness] has made assumptions about

  signal strength that call into question his estimate of where the

  phones were located at particular times, Defendants can test those

  assumptions on cross exam.”).

¶ 41   Here, both prosecution experts were subject to thorough

  cross-examination. Shanks also offered his own expert to challenge

  the accuracy of the prosecution’s evidence. That the experts

  disagreed did not undermine the reliability of the evidence or

  counsel against its admission in the first place. See Campbell, ¶ 42.

¶ 42   Thus, we also conclude that the district court did not abuse its

  discretion by admitting Ms. Battan’s and Agent Eicher’s testimony.

                      III.   Identification Evidence

¶ 43   Shanks contends that the district court erred by denying his

  motion to suppress the victim’s out-of-court identification.

  According to Shanks, the court further erred by admitting the

  victim’s in-court identification, which was based on the

                                    22
  impermissibly suggestive out-of-court identification. We disagree

  with both contentions.

                         A.        Standard of Review

¶ 44   “The ultimate question as to the constitutionality of pretrial

  identification procedures is a mixed question of law and fact.”

  Bernal v. People, 44 P.3d 184, 190 (Colo. 2002). Thus, “[w]hen

  reviewing a trial court’s denial of a motion to suppress, we generally

  defer to the trial court’s factual findings, but review its legal

  conclusions de novo.” People v. Plancarte, 232 P.3d 186, 189 (Colo.

  App. 2009). But while the trial court’s findings of historical fact are

  entitled to deference, “an appellate court may give different weight

  to those facts and may reach a different conclusion in light of the

  legal standard.” Bernal, 44 P.3d at 190; see People v. Singley, 2015

  COA 78M, ¶ 9.

                              B.    Applicable Law

¶ 45   To determine the admissibility of an out-of-court photographic

  identification, the court must engage in a two-step analysis. First,

  the defendant must prove that the identification procedure was

  impermissibly suggestive. Bernal, 44 P.3d at 191; Singley, ¶ 14. If

  the defendant fails to meet this initial burden, no further inquiry is

                                        23
  required and the identification is admissible. Bernal, 44 P.3d at

  191 (“It is important to note that these two steps must be completed

  separately; it is only necessary to reach the second step if the court

  first determines that the array was impermissibly suggestive.”);

  Singley, ¶ 14.

¶ 46   Second, if the court finds the photo array impermissibly

  suggestive, the burden shifts to the prosecution to show that the

  identification was nonetheless reliable under the totality of the

  circumstances. Bernal, 44 P.3d at 192; see also Singley, ¶ 15. “As

  long as the totality of the circumstances does not indicate a very

  substantial likelihood of irreparable misidentification, no

  constitutional impediment to the admission of the identification

  testimony exists.” Bernal, 44 P.3d at 192.

¶ 47   But a “defendant is denied due process when an in-court

  identification is based upon an out-of-court identification which is

  so suggestive as to render the in-court identification unreliable.”

  People v. Borghesi, 66 P.3d 93, 103 (Colo. 2003).

¶ 48   In determining whether the pretrial photo identification

  procedure is impermissibly suggestive, the court may consider such

  relevant factors as “the size of the array, the manner of its

                                    24
  presentation by the officers, and the details of the photographs

  themselves.” Bernal, 44 P.3d at 191. The size of the array is a

  factor affecting the weight a court gives to any irregularities. Id.

  Thus, the more pictures used, the less likely it is that a minor

  difference will have a prejudicial effect; the fewer pictures used, the

  closer the array must be scrutinized. Id.

¶ 49   The crucial question when examining the array itself is

  “whether the picture of the accused, which matches descriptions

  given by the witness, so stood out from all of the other photographs

  as to ‘suggest to an identifying witness that that person was more

  likely to be the culprit.’” Id. (quoting Jarerett v. Headley, 802 F.2d

  34, 41 (2d Cir. 1986)). “In other words, the array must not be so

  limited that the defendant is the only one to match the witness’s

  description of the perpetrator.” Id. The array need not include

  exact replicas of the defendant or be uniform with respect to a given

  characteristic, but they must be “matched by race, approximate

  age, facial hair, and a number of other characteristics.” Id. at

  191-92 (quoting People v. Webster, 987 P.2d 836, 839 (Colo. App.

  1998)). An array that includes a photo “unique in a manner directly

  related to an important identification factor” may be impermissibly

                                     25
  suggestive. Id. at 192; see also Grubbs v. Hannigan, 982 F.2d 1483,

  1490 (10th Cir. 1993) (“Although a photo-lineup is not necessarily

  suggestive merely because the individuals in the lineup differ in

  facial characteristics, . . . here the differences were either strikingly

  apparent, such as a swollen eye, or they related to an important

  component of [the victim’s] description of her assailant, his hair

  style.”).

¶ 50    We are in the same position as the district court to review the

  details of the photographs and consider their placement in the

  array. Thus, we review de novo whether the photographic array

  itself was impermissibly suggestive. See People v. Carlos, 41 Cal.

  Rptr. 3d 873, 876 (Cal. Ct. App. 2006) (reviewing the suggestibility

  of a photo array de novo); McCoy v. United States, 781 A.2d 765,

  771 (D.C. 2001) (same); Gamboa v. State, 296 S.W.3d 574, 581

  (Tex. Crim. App. 2009) (“We review de novo a trial court’s ruling on

  how the suggestiveness of a pre-trial photo array may have

  influenced an in-court identification.”); cf. People v. Ramadon, 2013

  CO 68, ¶ 21 (“When the interrogation is audio or video-recorded,

  and there are no disputed facts outside the recording pertinent to

  the suppression issue, we are in the same position as

                                     26
  the trial court in determining whether the statements should or

  should not be suppressed under the totality of the circumstances.”).

                              C.   Analysis

¶ 51   The victim described the second assailant as a “black Abe

  Lincoln” because he had “an Abe Lincoln style beard on his chin

  and high cheek bones.” The photo array presented to him

  contained pictures of six men arranged in two rows of three, with

  Shanks appearing in the middle of the bottom row. The men all

  appear to be African-American, though one man (not Shanks) has

  noticeably lighter skin than the other five. They all have similarly

  placed cheekbones, close-shaven haircuts, and some facial hair. 3

  They all appear to be of similar age. Officers presented the array in

  black-and-white, so there is no drastic difference in background

  color, lighting, or clothing color. All men appear to be wearing

  prison clothing. Each photograph is only of the head and neck and

  reveals nothing of the height or weight of the men.

  3 None of the men have particularly bushy sideburns or beards,
  which typically are associated with Abraham Lincoln. However, at
  trial, the victim testified that he used the description “black
  Abraham Lincoln” in reference to the $5 bill, which depicts Lincoln
  with closely-trimmed facial hair. In any event, Shanks’s facial hair
  does not distinguish him from the others in the photo array.

                                    27
¶ 52   Shanks points out that he is the only one with a pointy head,

  that he has small ears, and that his nose is broader than the rest.

  We agree that none of the other men have heads as pointy as

  Shanks’s or a nose that is quite as broad; however, several of the

  men do have long, slender faces and small ears, and their noses are

  a range of sizes. Further, the victim did not describe his assailant

  as having a pointy head, small ears, or a broad nose, so these are

  not defining characteristics that create impermissible

  suggestiveness. See Borghesi, 66 P.3d at 105; Bernal, 44 P.3d at

  192; People v. Owens, 97 P.3d 227, 233 (Colo. App. 2004).

¶ 53   Thus, we conclude that the photo array itself was not

  impermissibly suggestive and that the district court did not abuse

  its discretion by admitting it. Because we have concluded that the

  photo array was not impermissibly suggestive, we need not

  determine whether the identification was otherwise reliable under

  the totality of the circumstances.

¶ 54   Further, we conclude that the victim’s subsequent in-court

  identification of Shanks was not inherently unreliable. As noted,

  the in-court identification was not preceded by an impermissibly

  suggestive pretrial identification procedure, and there was nothing

                                       28
  suggestive about the in-court identification beyond the normal

  courtroom setting. See Garner v. People, 2019 CO 19, ¶ 5. Defense

  counsel was able to cross-examine the victim about the

  identification during the trial and to highlight for the jury any

  factors he believed made the in-court identification suggestive. See

  id. at ¶ 55. Thus, we also conclude that the district court did not

  err by admitting the in-court identification.

                     IV.    Alternate Suspect Defense

¶ 55   Shanks contends that the district court violated his rights to

  due process, to present a defense, and to a fair trial by denying his

  alternate suspect defense. We disagree.

                           A.   Standard of Review

¶ 56   We review the trial court’s evidentiary decisions, including

  whether to admit alternate suspect evidence, for an abuse of

  discretion. People v. Folsom, 2017 COA 146M, ¶ 29. A trial court

  abuses its discretion where its decision is manifestly arbitrary,

  unreasonable, or unfair, or “is based on an erroneous view of the

  law.” People v. Elmarr, 2015 CO 53, ¶ 20.

                                     29
                    B.    Applicable Legal Principles

¶ 57   A defendant has a constitutional right to present a defense,

  including the right to present evidence that someone other than the

  defendant may have committed the crime, because “a criminal

  defendant is entitled to all reasonable opportunities to present

  evidence that might tend to create doubt as to [his] guilt.” Folsom,

  ¶ 30 (quoting Elmarr, ¶ 26). To be admissible, however, the

  alternate suspect evidence must be relevant and its probative value

  must not be substantially outweighed by “the danger of unfair

  prejudice, confusion of the issues, or misleading the jury, or by

  considerations of undue delay, waste of time, or needless

  presentation of cumulative evidence.” CRE 403; see Elmarr, ¶ 27.

  Relevant evidence is evidence “having any tendency to make the

  existence of any fact that is of consequence to the determination of

  the action more probable or less probable than it would be without

  the evidence.” CRE 401.

¶ 58   “[T]he admissibility of alternate suspect evidence ultimately

  depends on the strength of the connection between

  the alternate suspect and the charged crime.” Elmarr, ¶ 22; accord

  Folsom, ¶ 31. The “evidence must create more than just an

                                    30
  unsupported inference or possible ground for suspicion.” Elmarr,

  ¶ 32. Instead, the evidence must establish a “non-speculative

  connection or nexus between the alternate suspect and the crime

  charged.” Id. Whether the requisite connection exists requires a

  case-by-case analysis considering all evidence proffered by the

  defendant to show that the alternate suspect committed the crime.

  Id.

¶ 59    The Colorado Supreme Court has held on numerous occasions

  that merely showing that an alternate suspect had the motive or the

  opportunity to commit the charged offense, without some additional

  proof connecting the alternate suspect to the offense, is insufficient

  to prove that necessary nexus. E.g., id. at ¶ 34 (“[E]vidence merely

  showing that someone else had a motive or opportunity to commit

  the charged crime — without other additional evidence

  circumstantially or inferentially linking the alternate suspect to the

  charged crime — presents too tenuous and speculative a connection

  to be relevant because it gives rise to no more than grounds for

  possible suspicion.”); People v. Mulligan, 193 Colo. 509, 518, 568

  P.2d 449, 456-57 (1977) (same).

                                    31
                       C.   Additional Background

¶ 60   Before trial, Shanks endorsed an alternate suspect defense,

  asserting that a man named Andrew Davis was the second

  assailant. Shanks’s endorsement stated the following:

         • Davis and Eastman were “associated” at the time of the

            offense;

         • Davis was at liberty and lived in the area of the offense at

            the time and therefore had the opportunity to commit it;

         • Eastman did not approve of Shanks’s relationship with

            her mother and the two had never gotten along;

         • Davis was associated with a gray Volkswagon Jetta and a

            witness described the car that dropped Cody off just after

            the offense as a gray Jetta;

         • Davis’s physical appearance more closely resembled the

            description given by the victim; and

         • Davis had an extensive criminal history involving

            menacing, weapons, and home invasions.

¶ 61   The prosecution moved to strike the endorsement and

  preclude Shanks from presenting alternate suspect evidence at

                                   32
  trial, arguing that the facts alleged were speculative and irrelevant

  to the charged offense. The court granted the prosecution’s motion.

¶ 62   At the beginning of trial, after it had become clear that

  Eastman would testify, defense counsel again asked for permission

  to introduce alternate suspect evidence. Counsel represented to the

  district court that Eastman had recently told her mother that Davis

  committed the crime with her and Cody, not Shanks.

¶ 63   The district court still found that the proffered evidence was

  not alternate suspect evidence and that there was “no actual

  connection” between Davis and the charged offense. The court did

  conclude, however, that the evidence could be used for

  impeachment, depending on Eastman’s testimony at trial. The

  court said that defense counsel could question Eastman about her

  relationship with Davis, about her covering up for him and lying to

  investigators, and about her dislike of Shanks. In addition, counsel

  likely would be allowed to introduce the photographs of Davis.

¶ 64   At trial, Eastman denied telling her mother that Davis helped

  commit the offense. She also testified that she was not dating Davis

  at the time. Her mother testified to the contrary and was shown

  pictures of Davis, which she confirmed accurately reflected his

                                    33
  appearance at that time. For reasons not pertinent to our analysis,

  no photographs of Davis were admitted at trial. Still, the court told

  defense counsel that he could argue in closing that Davis was an

  alternate suspect. Ultimately, counsel did not do so.

                              D.   Analysis

          1.   The District Court Did Not Abuse Its Discretion

¶ 65   The evidence Shanks first presented to the district court in

  support of his endorsement of an alternate suspect, even

  considered collectively, was speculative and did not provide a direct

  nexus between Davis and the offense. Generally, it demonstrated

  that Davis lived nearby at the time and was potentially dating one of

  the codefendants, thereby providing him the opportunity to commit

  the offense. But no one identified Davis as being involved in the

  offense, there was no physical evidence linking him to the offense,

  there was no evidence of a motive for him to commit the offense,

  there was no evidence about factual similarities between this

  offense and his previous crimes, and the victim confidently

  identified Shanks as the assailant. See Elmarr, ¶ 30 (“A defendant .

  . . suggesting that an alternate suspect committed the crime . . .

  might seek to show that someone else: had a motive to commit the

                                   34
  crime; had an opportunity to commit the crime; confessed to the

  crime or otherwise engaged in behavior indicating his involvement;

  is linked to physical evidence of the crime; or committed similar

  acts or crimes.”); Owens, 97 P.3d at 235 (affirming trial court’s

  exclusion of evidence that raised speculation but provided no

  “direct connection” between the alternate suspect and the crime);

  People v. Perez, 972 P.2d 1072, 1074-75 (Colo. App. 1998) (rejecting

  alternate suspect evidence based on commission of a similar crime

  when the evidence did not “indicat[e] any distinctive similarities in

  the details of the crimes”); cf. Folsom, ¶¶ 38-40 (reversing trial

  court’s exclusion of evidence that an alternate suspect, among other

  things, had been convicted of a similar crime in the same

  geographic area; had been linked to numerous other incidents in

  the area in the same general timeframe, including at least three

  incidents at the victim’s house; was identified by the victim as a

  person she recognized; and more closely matched the victim’s

  description than did the defendant).

¶ 66   And although Shanks told the district court on the morning of

  trial that Eastman would provide a direct link between Davis and

  the crime, Eastman actually testified that Davis was not involved

                                     35
  and denied that she had ever told her mother that Davis was

  involved. Thus, the evidence created nothing more than “an

  unsupported inference or possible ground for suspicion” that Davis

  committed the charged crimes. Under these circumstances, the

  district court did not abuse its discretion.

          2.    Any Error by the District Court Was Harmless

¶ 67   Even if we were to assume the district court erred by

  precluding certain alternate suspect evidence, we conclude that any

  such error was harmless. An evidentiary error precluding a

  defendant from presenting evidence may be of constitutional

  magnitude “only where the defendant was denied virtually his [or

  her] only means of effectively testing significant prosecution

  evidence.” People v. Brown, 2014 COA 155M-2, ¶ 6

  (quoting Krutsinger v. People, 219 P.3d 1054, 1062 (Colo. 2009)).

  Otherwise, reversal is required only if the error “substantially

  influenced the verdict or affected the fairness of the trial.” Brown, ¶

  6; see also Elmarr, ¶ 27 (“[T]he right to present a defense is

  generally subject to, and constrained by, familiar and well-

  established limits on the admissibility of evidence.”).

                                    36
¶ 68   Here, the district court did not preclude defense counsel from

  mentioning Davis or arguing his theory of defense that this was a

  case of mistaken identity. Defense counsel was still permitted to,

  and in fact did, attack Eastman’s credibility by questioning her and

  her mother about Davis’s involvement with Eastman and Eastman’s

  alleged statements to her mother that Davis was the second

  assailant. Thus, despite not receiving a jury instruction on

  alternate suspect evidence, the jury had before it sufficient evidence

  and argument to understand Shanks’s defense.

¶ 69   Accordingly, even if the district court erred in denying Shanks

  his alternate suspect defense, the error was harmless.

                         V.    Use of Nickname

¶ 70   Shanks contends the district court erred by admitting

  references to his nickname, “Capone,” which created unfair

  prejudice because the name is a “gang name.” We disagree.

               A.   Preservation and Standard of Review

¶ 71   The parties disagree as to whether this claim of error was

  preserved and what standard of review should apply. Shanks

  contends it was preserved by defense counsel’s objection to the

  prosecutor’s use of “Capone” as his “moniker” or “alias.” As the

                                    37
  transcript reveals, defense counsel suggested that the prosecutor

  use the word “nickname” instead of “moniker” or “alias,” the

  prosecutor revised his question accordingly, and the district court

  never ruled on the objection. Defense counsel did not otherwise

  object to the use of the nickname “Capone” throughout the balance

  of the trial.

¶ 72    We review a trial court’s decision to admit evidence for an

  abuse of discretion. People v. Clark, 2015 COA 44, ¶ 14. If the

  alleged evidentiary error is unpreserved, we reverse only if the error

  was plain. Hagos v. People, 2012 CO 63, ¶ 14. Plain errors are

  those that are obvious and substantial and so undermine the

  fundamental fairness of the trial itself as to cast serious doubt on

  the judgment of conviction. Id. Because we find the district court

  did not abuse its discretion, we need not resolve the parties’ dispute

  regarding preservation.

                              B.    Analysis

¶ 73    “[B]ecause ‘gangs are regarded with considerable disfavor by

  our society,’ gang-related evidence must be ‘admitted with care.’”

  Clark, ¶ 16 (quoting People v. Trujillo, 2014 COA 72, ¶ 72). Here,

  however, no evidence was presented that Shanks was in a gang,

                                    38
  that his nickname was affiliated with a gang, or that this offense

  was gang-related. Indeed, the word “gang” was not used once in

  front of the jury during trial. The only reason the nickname was

  used was because that is the name by which most of the witnesses

  knew Shanks. In fact, some of the witnesses did not even know his

  real name. And the prosecutor did not use the name as a way of

  introducing bad character evidence. It was used merely for

  identification, and to argue that the jury should discount good

  character testimony from Shanks’s family members because they

  did not even know he was nicknamed “Capone.”

¶ 74   Under these circumstances, we perceive no abuse of discretion

  in the district court’s decision to allow the use of the nickname.

  See People v. Samuels, 228 P.3d 229, 243 (Colo. App. 2009).

                         VI.   Cumulative Error

¶ 75   Lastly, Shanks contends that the cumulative effect of the

  errors raised in this appeal warrant reversal. We disagree.

¶ 76   “We will reverse for cumulative error where, although

  numerous individual allegations of error may be deemed harmless

  and not require reversal, in the aggregate those errors show

  prejudice to the defendant’s substantial rights and, thus, the

                                    39
  absence of a fair trial.” People v. Stewart, 2017 COA 99, ¶ 39

  (quoting People v. Gallegos, 260 P.3d 15, 28-29 (Colo. App. 2010));

  see People v. Mendenhall, 2015 COA 107M, ¶ 82. However, for the

  doctrine to apply, numerous errors must have been committed, not

  merely alleged. People v. Allgier, 2018 COA 122, ¶ 70.

¶ 77   Having found no errors, we reject this contention.

                            VII. Conclusion

¶ 78   The judgment is affirmed.

       JUDGE FURMAN and JUDGE DAVIDSON concur.

                                   40