Affirmed and Memorandum Opinion filed November 4, 2021.
In The
Fourteenth Court of Appeals
NO. 14-19-00498-CR
CHARLES MALCOLM ALYEA, Appellant
V.
THE STATE OF TEXAS, Appellee
On Appeal from the 184th District Court
Harris County, Texas
Trial Court Cause No. 1476015
MEMORANDUM OPINION
Appellant Charles Malcolm Alyea appeals his conviction of murder. In one
issue he contends that the trial court erred in admitting expert testimony regarding
cell phone tower data. We affirm.
RELIABILITY OF EXPERT TESTIMONY
In his sole issue appellant argues that the trial court abused its discretion by
allowing a detective to testify as an expert witness about the location of cellular
phones based on “call detail records that gave the location of the connected tower.”
Appellant argues that because the detective could not “go beyond the reports
provided by the cellular companies to explain the results they provided him, the
State failed to make a clear and convincing showing that the detective’s expert
conclusions had a reliable foundation.
A. General Legal Principles
Rule 702 of the Rules of Evidence provides that “[a] witness who is
qualified as an expert by knowledge, skill, experience, training, or education may
testify in the form of an opinion or otherwise if the expert’s scientific, technical, or
other specialized knowledge will help the trier of fact to understand the evidence or
to determine a fact in issue.” Tex. R. Evid. 702. Before admitting expert
testimony under Rule 702, the trial court must be satisfied that three conditions are
met: (1) the witness qualifies as an expert by reason of his knowledge, skill,
experience, training, or education; (2) the subject matter of the testimony is
appropriate for expert testimony; and (3) admitting the expert testimony will assist
the fact finder in deciding the case. Vela v. State, 209 S.W.3d 128, 131 (Tex.
Crim. App. 2006). These conditions are commonly referred to as (1) qualification,
(2) reliability, and (3) relevance. Id.
Texas Rule of Evidence 705(c) governs the reliability of expert testimony
and states that “[a]n expert’s opinion is inadmissible if the underlying facts or data
do not provide a sufficient basis for the opinion.” Tex. R. Evid. 705(c). The
reliability inquiry is flexible, at times focusing on the reliability of scientific
knowledge, at other times on the expert’s personal knowledge and experience.
Vela, 209 S.W.3d at 134. Indeed, experience alone may provide a sufficient basis
for an expert’s testimony. Id. The proponent of the expert must establish some
foundation for the reliability of the proffered expert’s opinion. Id.
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To be considered reliable, evidence from a scientific theory must satisfy
three criteria: “(a) the underlying scientific theory must be valid; (b) the technique
applying the theory must be valid; and (c) the technique must have been properly
applied on the occasion in question.” Coble v. State, 330 S.W.3d 253, 273 (Tex.
Crim. App. 2010) (quoting Kelly v. State, 824 S.W.2d 568, 573 (Tex. Crim. App.
1992)). When “soft” sciences are at issue, the trial court must inquire “(1) whether
the field of expertise is a legitimate one, (2) whether the subject matter of the
expert’s testimony is within the scope of that field, and (3) whether the expert’s
testimony properly relies upon and/or utilizes the principles involved in the field.”
Id. (quoting Nenno v. State, 970 S.W.2d 549, 561 (Tex. Crim. App. 1998)). “This
inquiry is somewhat more flexible than the Kelly factors applicable to Newtonian
and medical science. Id. The general principles announced in Kelly apply, but the
specific factors outlined in those cases may, or may not apply depending upon the
context. Id. Regardless, under both Kelly and Nenno, reliability should be
evaluated by reference to the standards applicable to the professional field in
question. Id.
We review a trial court’s decision on whether to allow expert testimony for
an abuse of discretion. Gallo v. State, 239 S.W.3d 757, 765 (Tex. Crim. App.
2007). Before reversing the trial court’s decision, we must find the trial court’s
ruling was so clearly wrong as to lie outside the realm within which reasonable
people might disagree. See Taylor v. State, 268 S.W.3d 571, 579 (Tex. Crim. App.
2008); Green v. State, 191 S.W.3d 888, 895 (Tex. App.–Houston [14th Dist.] 2006,
pet. ref’d). Absent a clear abuse of discretion, the trial court’s decision to admit or
exclude expert testimony will not be disturbed. Wyatt v. State, 23 S.W.3d 18, 27
(Tex. Crim. App. 2000).
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B. Background
The State called a detective with the Harris County Sheriff’s Office as an
expert to testify on the approximate location of appellant’s cell phone before,
during, and after the murders using appellant’s cell phone records, one of the
complainant’s cell phone records, and a list of the cell phone towers in the area.
The trial court conducted a hearing outside the presence of the jury to consider
appellant’s motion to exclude the detective’s expert testimony.
At the hearing, the detective testified about his qualifications to opine on
these subjects. He stated that he had been with the Harris County Sheriff’s Office
for sixteen years and investigating homicides for six years. The detective had sixty
to seventy credited training hours in “cell phone related investigations” and another
twenty to thirty hours working with another officer in the Houston Police
Department.1 He has also testified in other cases about cell phone mapping and
that he uses an application of cell phone data in approximately 90% of his cases.
The detective has looked at hundreds of cases with multiple phones in each case,
using the cell phone data and “examining it.” The detective testified that he was
not a “scientist” on cell phone towers and could not go into the “underlying
theories and why scientists believe that is a good science” behind cell phone tower
mapping, that he could just read the data produced from the cell phone carriers.
The detective also testified that the data was “good” because it had been used in
thousands of courtrooms across the country and supported by the judges in those
courtrooms.
The detective testified that he used the calls made in the cell phone records
to plot distances from the cell towers connected to, to create “sectors” to generally
1
The officer that the detective worked with was “one of the longest tenured members of
[the Houston Police Department’s] criminal intelligence division who has testified in hundreds of
trials with regard to cell phone mapping.”
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estimate where the cell phone is located at the time of the call. He explained that
multiple phone calls made “eliminates the possibility of being off target. The more
you have, the more information there is, the easier it is to paint that picture.” In
this case the detective also used witness statements and surveillance footage to
confirm that the data provided in the cell phone records was accurately portraying
the sector plotted from the data. The detective also used additional records, such
as cell phone records of other persons, to corroborate his findings or show how his
findings might be faulty.
When asked whether it was possible that all the calls may have been routed
to one tower, the detective testified that the calls could not have all been routed to
one tower because when calls are being routed “off tower,” the records will
mention that in the report. In addition to compiling the findings into a PowerPoint
presentation, the detective sent his findings to another officer with the Houston
Police Department for peer review. The detective also provided a report on his
analysis and findings. The report states that “cell phones constantly monitor their
environment, continuously communicating with the cellular network and looking
for the best signal and tower (antenna) to camp on.”
The trial court concluded that the detective’s testimony about the mapping
done from the cell phone records was admissible and complied with Rule 702 of
the Rules of Evidence.
C. Analysis
Appellant argues that the State failed to prove that the conclusions about the
cell phones’ locations based on cell tower data were reliable, namely that the data
that was used to compile the reports about the cell phone location was not proved
to be reliable by the State. Appellant further argues that the detective wrongly
assumed that cell phones always connect to the closest tower.
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Here, the detective did not simply rely on the information in the reports
provided by the cellular phone companies, but instead used other information to
help identify faults or corroborate his findings based on the reports. Appellant’s
argument is that the detective needs to know the underlying particularities
regarding how cell phones connect or choose connections to cell towers before
being able to testify reliably, but as other courts have concluded, this knowledge is
not relevant to the “relatively simple task” of mapping the general location of the
cell phone by using towers identified in the call records. See Thompson v. State,
425 S.W.3d 480, 489 (Tex. App.—Houston [1st Dist.] 2012, pet. ref’d); Robinson
v. State, 368 S.W.3d 588, 601 (Tex. App.—Austin 2012, pet. ref’d); see also Ward
v. State, No. 14-15-00473-CR, 2016 WL 6238339, *10 (Tex. App.—Houston [14th
Dist.] Oct. 25, 2016, pet. ref’d) (mem. op., not designated for publication).
Appellant argues that the detective could only say with confidence that the
phone connected to a cell site somewhere within a radius of twenty miles, but
because of the detective’s assumption that a cell phone would connect to the
nearest tower the detective’s testimony is “unrealistic and untenable.” Regarding
the allegation that the detective testified that a cell phone always connects to the
closest tower, the record does not bear this out. The detective testified that he
reviewed the cell phone records provided by the carriers, in this case AT&T and T-
Mobile, to determine which tower the phones connected to at specific times during
the relevant dates. Specifically, the detective reviewed records from appellant’s
phone beginning on April 30, 2015, and ending on May 1, 2015. The detective
also reviewed records from one of the complainant’s phones beginning on April
30, 2015, and ending on May 1, 2015. The records themselves show the tower
connected to by the phone, there was no interpretation involved. The detective
testified that if a call was being routed “off-tower” that it would be indicated in the
records provided by the carrier, but that such an indication would not change the
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location of the phone in relation to the tower. The detective also testified that a
situation in which every call was routed to one tower would not happen.
The detective testified that he could “read the data that [the carriers] provide
so that I can tell you the general location of a cell phone based on the information
provided and where towers are located.” The detective testified that he could not:
give an exact distance of where the phone is going to be in relation to
the tower. I can give a sector. What we do is generally estimate
distances. Distances from the tower to where the phone should be or
sector ends is a better term or generally estimated from approximately
one half to two thirds the distance between the towers. Again, that’s
an estimate.
[I]f all you have is one phone call, you can say, I suppose something
could have gone haywire there. When you have multiple phone calls,
that eliminates the possibility of it being off target. The more you
have, the more information there is, the easier it is to paint that
picture.
The detective’s report states that cell phones monitor their environments to look
for the best signal, not necessarily the closest signal.
The detective took the data provided by the cellular phone companies and
placed that data into the “field” by locating each cell site on a mapping program.
The detective located the cell site from a satellite picture and then from a street
view picture. The detective then connected the locations of those cell sites to other
geographic locations of interest in the case, such as the murder scenes, the homes
of appellant and one of the complainants, the home of other witnesses, the home of
appellant’s parents, and a gas station where appellant purchased lighter fluid. The
detective also indicated that he checked his results through other evidence he
collected in the case, such as the surveillance video at the Shell station where
appellant purchased lighter fluid the night of the murders, as well as witness
statements about where the appellant or one of the complainants were at different
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times on the night of the murders. Lastly, the detective indicated that his results
were reviewed by another officer in the Houston Police Department.
The detective did not testify that the cell phones used by appellant and the
complainant were necessarily closest to the towers that they connected to, just that
the towers told him the direction the phones connected from and that it limited the
location of the phones to a certain geographic sector. For instance, the detective
testified that between 11:30 p.m. and 11:51 p.m. on April 30, 2015, both the
appellant and a complainant were “somewhere in the vicinity of Cloverleaf” and
“somewhere in the vicinity of the eastern portion of Cloverleaf.” The detective
indicated that, because enough calls were made, he had sufficient information to
see the “general way they traveled” but couldn’t tell what streets or routes were
taken. In his analysis, the detective used multiple cell tower connections over
many hours, which he testified reduced the likelihood of any error.
Appellant also provides case examples to illustrate how wrongful
convictions may be obtained from this type of testimony. However, appellant fails
to detail how the evidence was faulty in the overturned cases or how such
principles are applicable to the case at hand. For instance, in one of appellant’s
case examples, Lisa Roberts’s ex-girlfriend was murdered, and her body was found
in a park. Roberts v. Howton, 13 F. Supp. 3d 1077, 1081 (D. Or. 2014).
Detectives reviewed Roberts’s cell phone records and found that her phone
connected to a tower within four miles of the park where the body was found on
the morning of the murder. Id. at 1086–88. When confronted with this
information, Roberts’s defense counsel recommended that she plead guilty to the
lesser charge of manslaughter. Id. at 1101. Roberts accepted the plea. Id. Years
later upon petition for writ of habeas corpus, the court concluded that her defense
counsel had rendered ineffective assistance for failing to hire their own expert
witness to investigate the cell phone records and tower data to put on evidence to
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refute the prosecutor’s possible expert witness testimony. Id. As part of the writ
proceeding, in order to show that refuting the conclusions drawn by the
prosecutor’s expert was possible, Roberts attached expert reports from two experts
to support her assertion that had her counsel conducted a reasonable investigation
or consulted with an expert, he would have understood the evidence against
Roberts better and advised her accordingly. Id. at 1102. The court concluded that
counsel’s conduct fell below an objective standard of reasonableness because his
“assessment of the evidence, and his failure to retain an expert, was not based upon
a reasonable investigation or understanding of the evidence.” Id. “[T]he
presentation of expert testimony at trial, concerning the variables impacting the
reliability of the cell tower evidence to pinpoint the caller’s location, likely would
have changed the outcome of the trial.” Id.
In this case, the detective merely offered geographic sectors from the records
provided.2 The detective did not purport to offer a “pin-point” location of the
appellant on the dates analyzed. Appellant was permitted to cross-examine the
detective and highlight that the particular methodology used is subject to
limitations. See Daubert v. Merrell Dow Pharm., Inc., 509 U.S. 579, 596 (1993)
(“Vigorous cross-examination, presentation of contrary evidence, and careful
instruction on the burden of proof are the traditional and appropriate means of
attacking shaky but admissible evidence.”).
Under the circumstances presented herein, based on the testimony of the
detective and how he arrived at his conclusions and that they were supported by
2
Texas appellate courts have repeatedly classified this type of testimony as non-complex
and relatively “straight-forward.” See Thompson v. State, 425 S.W.3d 480, 488–89 (Tex. App.—
Houston [1st Dist.] 2012, pet. ref’d); Robinson v. State, 368 S.W.3d 588, 599–601 (Tex. App.—
Austin 2012, pet. ref’d); Ward v. State, 14-15-00473-CR, 2016 WL 6238339 (Tex. App.—
Houston [14th Dist.] Oct. 25, 2016, pet. ref’d) (mem. op., not designated for publication);
Patterson v. State, 05-13-00450-CR, 2015 WL 2400809 (Tex. App.—Dallas May 19, 2015, pet.
ref’d) (not designated for publication).
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other data, such as eyewitness testimony, surveillance footage at the Shell station,
and camera footage from the homes of witnesses that corroborate the detective’s
expert report, we cannot conclude that the trial court abused its discretion in
determining the expert’s testimony regarding the location of the cell phones based
on the cell phone records was reliable in this case. See Rhomer v. State, 569
S.W.3d 664, 672 n.1 (Tex. Crim. App. 2019) (“Reliability is evaluated by looking
at the method the expert used to come to his conclusions. [The expert’s] testimony
was reliable because it was based on the information he gathered at the scene: the
measurements he took, the pictures he captured, the damage he observed, and the
diagram he created.”); see also William v. State, 606 S.W.3d 48, 56 (Tex. App.—
Houston [1st Dist.] 2020, pet. ref’d) (“The task [the expert] was called upon to
perform was not complex and it was verifiable. . . . Cell phone records showed the
exact tower to which the phone connected, and [the expert] testified that she
checked the records for accuracy. . . . the trial court did not abuse its discretion
when it determined that [the expert’s] opinion on the general location of . . . the
phones was reliable.”).
We overrule appellant’s sole issue on appeal.
CONCLUSION
Having overruled appellant’s sole issue on appeal, we affirm the judgment
of the trial court.
/s/ Ken Wise
Justice
Panel consists of Justices Wise, Bourliot, and Spain.
Do Not Publish — TEX. R. APP. P. 47.2(b).
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