MEMORANDUM OF DECISION AND ORDER ON DEFENDANTâS
MOTION TO EXCUDE NON-EXPERT TESTIMONY CONCERNING GPS
MONITORING AND TRACKING
B. Gordon, Justice of the Superior Court
Defendant Mannix Lewis has moved in limine for an
order excluding evidence and testimony pertaining to Mr.
Lewisâs GPS device and its monitoring and tracking of his
physical positions on the date and at the time of the crime.
The gravamen of the Defendantâs motion is the charge that GPS
technology has not achieved a sufficient level acceptance and
reliability to allow for the admission of its data into
evidence. The Defendant seeks a Daubert/Lanigan
hearing to address this issue. In the alternative, and wholly
apart from the putative unreliability of the technology, the
Defendant submits that there is no genuine dispute as to his
physical position in the area of Main and Shepard Streets on
May 1, 2014. Thus, it is argued, GPS evidence is needlessly
cumulative, and trial references to Mr. Lewisâs wearing of
the device will unfairly prejudice him by inviting jury
speculation as to the prior bad acts that gave rise to
the Courtâs conclusion that the reliability of GPS technology
is today so broadly accepted in the scientific and legal
community that no Daubert/Lanigan hearing is
necessary to establish the admissibility of its position data
in this case. In Commonwealth v. Thissell, 457 Mass.
191 (2010), the Supreme Judicial Court considered whether
GPS-based records of a defendantâs movements were
sufficiently reliable to serve as the basis for a probation
revocation. The records at issue were activity reports
showing the defendantâs time-specified location within
particular exclusion zones, and were introduced at hearing
through a probation officer who was not an "expert"
in GPS technology. Id. at 193-95. The probation
officer simply testified that the GPS apparatus transmits a
signal to a satellite, and that a central monitoring center
is on this basis able to pinpoint a probationerâs location.
Id. at 193. Addressing a due process challenge to
the admissibility of the records, the SJC declared: "To
the extent they rely on GPS technology, that technology is
widely used and acknowledged as a reliable indicator of time
and location data." Reinforcing this conclusion, the
undersigned observes that GPS technology has been
specifically approved by the Legislature for use in
monitoring certain criminal offenders who are sentenced to
probation or subject to parole, see, e.g.,
Mass. G.L. c. 265, § 47, a fact the Thissell
Court itself took note of in its ruling. Id. at 198
n.15. See also State v. Brown,
2018 WL 4101065, at *5 (S.C. 2018) (citing Thissell
and stating, "we acknowledge that the reliability or
operation of GPS technology in general is not genuinely
disputed," but noting that GPS records must still be
authenticated for accuracy).
First Circuit Court of Appeals has similarly held that expert
testimony is not required to validate GPS evidence. In
United States v. Espinal-Almeida, 699 F.3d 588 (1st
Cir. 2012), cert. denied, 569 U.S. 936
(2013), GPS data was introduced at trial and explained
through the testimony of a lay witness from U.S. Customs
(Durand). Durand retrieved and analyzed coordinates
information in connection with a drug trafficking case in
which a GPS device was aboard a boat that had conducted an
alleged transfer of narcotics. Id. at 608. The
defendant objected "that the government did not
establish the accuracy or reliability of the processes
employed by the GPS itself or the Garmin and Google Earth
software." Id. at 608. The defendant likewise
argued that, due to the specialized and technical nature of
the GPS evidence, an expert witness was needed to
authenticate it. Id. The First Circuit disagreed:
"The issues surrounding the processes employed by the
GPS and software, and their accuracy, were not so
scientifically or technologically grounded that expert
testimony was required to authenticate the evidence, and thus
the testimony of Durand, someone knowledgeable, trained, and
experienced in analyzing GPS devices, was sufficient to
authenticate the the GPS data and software generated
Id. at 612-613.
courts confronting GPS evidence have reached the same
conclusion. In United States v. Brooks, 715 F.3d
1069 (8th Cir. 2013), for example, the Eighth Circuit Court
of Appeals held that it was proper for a trial judge to take
judicial notice of the reliability of GPS technology to
satisfy the requirements of Fed.R.Evid. 702. The district
court had denied the defendantâs motion for a
Daubert hearing to challenge the "reliability,
accuracy, and underlying soundness of the science"
behind GPS evidence, see United States v.
Brooks, 2012 WL 12895351, at *4 (S.D. Iowa) (noting
"the nearly universal acceptance by other courts of the
reliability of this technology"), and the Court of
Appeals affirmed. The Court wrote:
"Commercial GPS units are widely available, and most
modern cell phones have GPS tracking capabilities. Courts
routinely rely on GPS technology to supervise individuals on
probation or supervised release, and in assessing the Fourth
Amendment constraints associated with GPS tracking, courts
generally have assumed the technologyâs accuracy."
Id. at 1078. See also United
States v. Matthews, 250 F.Supp.3d 806, 818-19 (D. Colo.
2017) (denying defense motion for Daubert hearing on
witnessâs qualifications to testify concerning GPS data from
defendantâs ankle bracelet, concluding that any challenge to
the accuracy of GPS data was a matter for cross-examination
and not an issue of admissibility).
same connection, the Eighth Circuit rejected the contention
that it was improper to allow a lay witness, an account
executive with the GPS manufacturer, to testify concerning
the operation of GPS, given the witnessâs training and
experience demonstrating the device to customers.
Brooks, 715 F.3d at 1078. Accord United
States v. Thompson, 393 Fed.Appx. 852, 858 (3d Cir.
2010), cert. denied, 562 U.S. 1262 (2011)
(district court properly allowed lay witness to testify as to
functioning GPS device).
undersigned finds these authorities to be persuasive, and
believes the Supreme Judicial Court will take judicial notice
of the reliability of GPS technology if and when presented
with the issue. The SJC has followed such a course in
analogous circumstances. See, e.g.,
Commonwealth v. Whynaught, 377 Mass. 14, 17 (1979)
(taking judicial notice of radar speedometer as accurate and
reliable means of measuring velocity); Commonwealth v.
LePage, 352 Mass. 403, 419 (1967) (stating that the
capacity of trained dogs to follow a humanâs trail by scent
has long been known). Cf. Commonwealth v.
Augustine, 2013 WL 5612574, at *1 n.2 (Mass. Super. Ct.)
(noting that parties had agreed trial court could take
judicial notice of facts relating to cell site location
technology), vacated by Augustine,
467 Mass. 230 (2014). Accordingly, the Court rejects the
Daubert/Lanigan challenge the Defendant has brought
forward in respect to the GPS location data that the
Commonwealth proposes to introduce at trial.
Defendantâs alternative argument that introducing GPS
evidence would be cumulative (given that Mr. Lewisâs physical
location at the time of the crime is not in dispute), and
that introducing such evidence would implicitly taint him
with unspecified prior bad acts, represents a closer question
for the Court. It is true that Mr. Lewis does not intend to
present alibi evidence or otherwise contest his presence at
the scene of the crime. This would seem to invest GPS data
concerning his physical location with limited probative
value. That said, the Commonwealth has every right to present
a full narrative of how it came to arrest and charge Mr.
Lewis with the crimes at issue in this case, particularly in
light of the Defendantâs declaration that he intends to
present a Bowden defense. For this reason, some
amount of cumulative evidence must be tolerated where the
prosecution bears the burden of proving the Defendantâs guilt
beyond a reasonable doubt.
the speculation about prior bad acts and criminal character
that referencing a GPS device arguably invites, the Court is
confident that the jury can be provided with a limiting
instruction that effectively mitigates this risk.
See Mass. G. Evid. § 404(b), at 56 (2018 ed.).
In its discretion to balance evidentiary relevance and
prejudice, therefore, the Court will not bar the Commonwealth
from making reference to data generated by the GPS device Mr.
Lewis was wearing at the time of the alleged crime. The
Commonwealth will not, however, disclose the specific reasons
Mr. Lewis was wearing a GPS; and the jury will be instructed
that persons may wear such devices in a broad range of
circumstances, and that any GPS-based inference that the
Defendant has either a violent character or propensity to
crime is strictly forbidden.