State v. Simmer

304 Neb. 369

935 N.W.2d 167

STATE of Nebraska, appellee,

v.Charles M. SIMMER, appellant.

No. S-18-500.

Supreme Court of Nebraska.

Filed November 1, 2019

Thomas C. Riley, Douglas County Public Defender, for appellant.

Douglas J. Peterson, Attorney General, and Melissa R. Vincent, Lincoln, for appellee.

Heavican, C.J., Miller -Lerman, Cassel, Stacy, Funke, Papik, and Freudenberg, JJ.

Papik, J. Charles 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.

I. BACKGROUND

1. OVERVIEW

On 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.

When 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.

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.

At the 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.

The sections below summarize the Daubert / Schafersman proceedings and the relevant evidence at trial.

2. DAUBERT /SCHAFERSMAN PROCEEDINGS

At 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 program. Simmer elicited testimony from Nathaniel Adams to challenge TrueAllele’s methodology.

(a) Testimony of Helligso

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 match happening."

Helligso 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.

Helligso 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.

In this case, among the items that Helligso received in 2007 were swabs obtained from one of the knife handles and 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.

In 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."

Helligso 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 validation process:

[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 [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 determine if you have a mixture, but, in general, no, we don't look at those peaks then.

Helligso explained that at UNMC, none of the data below the threshold is used in her statistical calculations.

Helligso testified that Cybergenetics had developed a software program that is not bound by data thresholds. Using a series of mathematical calculations, the software analyzes every peak to determine whether it is "an artifact [or] a real allele." Helligso also testified that Perlin does not retest the evidence; rather, his software simply uses all the data compiled by the laboratory during its analysis. Helligso testified that the human brain could perform the same calculations as the software, but it would require "an extreme amount of time." She stated that it makes sense to use software that performs the necessary calculations quickly and accurately.

Helligso testified that probabilistic genotyping has "definitely been a hot topic for a couple of years now." When Helligso was asked whether there was some dispute about the general acceptance of Perlin’s approach in the broader scientific community, Helligso replied, "[I]f you [had] asked me that question six or seven years ago, I would have agreed, but I would say now within the last five years that, in general, the community is — is agreeing that these types of software programs are necessary." The number of people who do not agree are "becoming fewer and fewer." She pointed out that TrueAllele addresses a need in the DNA analysis community by facilitating the use of all of the DNA data to calculate a "good statistic." Helligso noted that the accuracy of TrueAllele software had been tested over at least 10 years with thousands of known profiles with an "extremely high success rate." She also noted that a similar program, "STRmix," is "being highly touted by the FBI and the national government" and "has kind of taken off to where lots of laboratories have those."

(b) Testimony of Perlin

As noted above, Perlin is the chief scientist and executive officer at Cybergenetics, a bioinformation company. He testified about his company’s software, TrueAllele, and its application in Simmer’s case.

Perlin explained that TrueAllele is designed to separate the various contributors to DNA samples processed by crime laboratories and assess the likelihood that a contributor matches a known sample. Like Helligso, Perlin...