Expert Witnesses: Appeal and Error. The
standard for reviewing the admissibility of expert testimony
is abuse of discretion.
Judgments: Expert Witnesses: Words and
Phrases. An abuse of discretion in the trial
court's determination under Daubert v. Merrell Dow
Pharmaceuticals, Inc., 509 U.S. 579, 113 S.Ct. 2786, 125
L.Ed.2d 469 (1993), and Schafersman v. Agland Coop,
262 Neb. 215, 631 N.W.2d 862 (2001), occurs when a trial
court's decision is based upon reasons that are untenable
or unreasonable or if its action is clearly against justice
or conscience, reason, and evidence.
Courts: Expert Witnesses. Under the
Daubert v. Merrell Dow Pharmaceuticals, Inc., 509
U.S. 579, 113 S.Ct. 2786, 125 L.Ed.2d 469 (1993), and
Schafersman v. Agland Coop, 262 Neb. 215, 631 N.W.2d
862 (2001), framework, the trial court acts as a gatekeeper
to ensure the evidentiary relevance and reliability of an
Trial: Expert Witnesses: Intent. The purpose
of the gatekeeping function is to ensure that the courtroom
door remains closed to "junk science" that might
unduly influence the jury, while admitting reliable expert
testimony that will assist the trier of fact.
Trial: Expert Witnesses. A trial court can
consider several nonexclusive factors in determining the
reliability of an expert's opinion: (1) whether a theory
or technique can be (and has been) tested; (2) whether it has
been subjected to peer review and publication; (3) whether,
in respect to a particular technique, there is a high known
or potential rate of error; (4) whether there are standards
controlling the technique's operation; and (5) whether
the theory or technique enjoys general acceptance within a
relevant scientific community.
___. Once the reasoning or methodology of an expert opinion
has been found to be reliable, the court must determine
whether the [304 Neb. 370] expert's reasoning or
methodology can be properly applied to the facts in issue.
from the District Court for Douglas County: Thomas A. Otepka,
C. Riley, Douglas County Public Defender, for appellant.
Douglas J. Peterson, Attorney General, and Melissa R. Vincent
Heavican, C.J., Miller-Lerman, Cassel, Stacy, Funke, Papik,
and Freudenberg, JJ.
M. Simmer appeals his conviction for first degree murder. DNA
evidence presented at Simmer's jury trial linked him to
the crime. The sole issue presented by this appeal is whether
the district court erred in admitting DNA analysis conducted
by using TrueAllele probabilistic genotyping software, over
Simmer's Daubert/Schafersman challenges. Finding
no abuse of discretion, we affirm.
November 3, 2007, Simmer's aunt, Joy Blanchard, was
murdered in her home. She was discovered lying face down on
the floor with two knives protruding from her neck. Close by
was a spindle broken from the nearby bannister. An autopsy
revealed the cause of death to be blunt force trauma and stab
wounds to the head and neck.
law enforcement processed the crime scene, they swabbed
several items for DNA, including the spindle, the handles on
both knives, and the interior doorknob on the front door of
the residence. DNA testing and analysis conducted in 2015 and
2016 indicated the presence of Simmer's DNA on one of the
knife handles and the interior doorknob.
Neb. 371] On June 7, 2016, Simmer was charged by information
in Douglas County District Court with one count of first
degree murder, a Class IA felony. Prior to trial, Simmer
filed a motion in limine asserting a challenge to DNA
analysis performed by Cybergenetics, Inc., which challenge
was pursuant to Daubert v. Merrell Dow Pharmaceuticals,
Inc., 509 U.S. 579, 113 S.Ct. 2786, 125 L.Ed.2d 469
(1993), and Schafersman v. Agland Coop, 262 Neb.
215, 631 N.W.2d 862 (2001) (Daubert/Schafersman). He
sought to preclude the State from introducing at trial
"any and all testimony concerning DNA testing and the
results of said testing," including
"identification" and "comparison" of DNA
testing. Simmer alleged that the reliability of the theories,
techniques, and procedures used by the State's experts
had not been established and that the proposed testimony was
"based on insufficient facts and data." Hearings
were held on the motion, and the district court overruled it.
subsequent jury trial, Simmer preserved the
Daubert/Schafersman challenges raised in his
pretrial motion. He lodged a continuing objection when Dr.
Mark Perlin, the chief scientist and executive officer at
Cybergenetics, was called to testify about TrueAllele
probabilistic genotyping and its application in this case.
The district court overruled the objection. The jury heard
DNA evidence and other circumstantial evidence connecting
Simmer to Blanchard's murder, and Simmer was convicted of
the crime charged and sentenced to life imprisonment.
sections below summarize the Daubert/Schafersman
proceedings and the relevant evidence at trial.
pretrial proceedings on Simmer's motion in limine, the
district court received exhibits and heard expert testimony
about DNA evidence from three witnesses. Generally, Mellissa
Helligso's testimony provided context for Perlin's
testimony about Cybergenetics' TrueAllele probabilistic
genotyping [304 Neb. 372] program. Simmer elicited testimony
from Nathaniel Adams to challenge TrueAllele's
Testimony of Helligso
a forensic DNA analyst employed by the University of Nebraska
Medical Center (UNMC), testified about the DNA tests that she
performed in this case. Helligso explained the process by
which an autosomal DNA profile is obtained and analyzed. Upon
receiving evidence containing biological material, she
extracts the DNA, quantifies and amplifies it, and ultimately
runs it through a genetic analyzer. The genetic analyzer
generates a DNA profile that can then be compared to DNA from
known individuals. Typically, the analysis is limited to
specific locations in the DNA and does not include a full
profile. If she identifies consistencies between the evidence
profile and the known individual's profile, she will
"generate a statistic to show the likelihood of that
also explained the difference between autosomal DNA and Y-STR
DNA. Humans have 23 pairs of chromosomes with each pair
consisting of one each from the father and mother. The term
"allele" describes the varying forms of a gene that
can be specific to an individual but found for everyone at
the same place in the same chromosome. Differences in alleles
at predetermined chromosome locations, referred to as
"loci," define a person's DNA profile and can
be used for comparison with evidence samples.
explained that autosomal DNA is composed of DNA inherited
from both parents. Y-STR DNA, on the other hand, involves
only the Y chromosome, which is found only in males and is
passed from father to son. Because all males in the same
family have the same Y-STR DNA, it cannot identify a
particular male within that family and is less discriminating
than autosomal DNA. In Y-STR DNA testing, a DNA extract is
amplified with a particular "kit" that only looks
at the Y-STR locations found on the Y chromosome.
case, among the items that Helligso received in 2007 were
swabs obtained from one of the knife handles and [304 Neb.
373] the spindle. Y-STR DNA testing of both items disclosed
the presence of two Y chromosomes, indicating a mixture of
two males. Simmer could not be excluded as the major male
contributor in either sample, but neither could his brother,
since they share the same Y chromosome. The probability of a
match was stronger on the knife handle than on the spindle.
November 2015, Helligso received several additional items for
testing, including a swab from the interior doorknob on the
front door to Blanchard's residence. Helligso determined
the sample contained autosomal DNA from at least two
individuals. Neither Blanchard nor Simmer could be excluded
as full contributors on the doorknob, and "[t]he
probability of a random individual matching a DNA profile
within the mixture, given that . . . Simmer expresses such a
profile, [was] 1 in 357 million . . . for Caucasians, 1 in
844 million . . . for African Americans, and 1 in 2.37
billion . . . for American Hispanics."
suggested sending her work to Perlin at Cybergenetics for
additional analysis. To provide the background for that
decision, Helligso explained the process by which a DNA
profile is obtained and analyzed and the significance of data
"thresholds." She stated that for any type of
testing done by UNMC, the laboratory must go through a
[O]ne of the things that you have to establish is your
threshold, which is the height at which, in your laboratory,
you can determine the difference between what would be
considered a real peak or real allele and background noise of
the instrumentation, because every instrument has background
noise just by the technology in which it works. And so every
laboratory, for their own instrumentation, has to determine
where that cutoff lies within the data.
... In our laboratory, the threshold for autosomal, and I
believe for Y-STR in this case as well, was set at 50 [304
Neb. 374] [relative fluorescence units (RFU)]. So any peak
that is below 50 RFU does not get labeled by the software
program that we have, so then we, in general, do not look at
those peaks. They can be considered if you're trying to