Motion to Amend Witness List and Expert Disclosures

Filed: 06/12/2025 09:32:10 Fourth Judicial District, Ada County Trent Tripple, Clerk of the Court
By: Deputy Clerk-Waters, Renee
LATAH COUNTY PROSECUTOR'S OFFICE

WILLIAM W. THOMPSON, JR., ISB No. 2613
PROSECUTING ATTORNEY

ASHLEY S. JENNINGS, ISB No. 8491
SENIOR DEPUTY PROSECUTING ATTORNEY

JOSHUA D. HURWIT, ISB. No. 9527
SPECIAL DEPUTY PROSECUTING ATTORNEY

Latah County Courthouse 522 S. Adams Street, Ste. 211 Moscow, ID 83843
Phone: (208) 883-2246 paservice@latahcountyid.gov
IN THE DISTRICT COURT OF THE FOURTH JUDICIAL DISTRICT OF THE
STATE OF IDAHO, IN AND FOR THE COUNTY OF ADA

STATE OF IDAHO, Case No. CR01-24-31665 Plaintiff,
V. MOTION TO AMEND WITNESS

LIST AND SUPPLEMENT

BRYAN C. KOHBERGER, EXPERT DISCLOSURES

Defendant.

COMES NOW the State of Idaho, by and through the Latah County Prosecuting Attorney, and respectfully moves the Court for permission to amend the State's witness list and to supplement previously filed expert disclosures by adding Dr. Christian Westring as a potential expert witness.

The State makes this Motion to add the above-referenced witness to testify about an issue that the State believed had been resolved-namely, that Defendant was found not to be a contributor to a DNA mixture found under one victim's fingernail. The State proposed a stipulation to this effect, but Defendant informed the State that he will not so stipulate because he
MOTION TO AMEND WITNESS LIST AND SUPPLEMENT EXPERT DISCLOSURES 1

prefers to present testimony about this fact. Thus, the State will likely need to call Dr. Christian Westring, to testify about the DNA mixture so that the jury can understand the State's position and not be misled into believing that there is factual dispute where none exists.

On February 24, 2025, Defendant filed a “ Motion in Limine # 5 Re: Inconclusive Data. " This motion centered around a DNA mixture found under victim Madison Mogen's fingernail (Item 13.1) and the Idaho State Police Forensic Laboratory's (ISP Lab) conclusion that it was “ inconclusive ” whether Defendant was a contributor to this mixture. As Dr. Westring explained in his affidavit (see below), that conclusion is a result of limitations imposed on ISP Lab staff by certain internal policies; but the State did not intend to argue or imply that Defendant was a contributor to the DNA mixture, and it has maintained this position since the issue was first raised.

Thus, the State retained Dr. Westring to review the DNA testing and the computational analysis of the data. In response to the Defendant's Motion, on April 7, 2025, the State filed an affidavit for Dr. Westring (attached as Exhibit S-1). In summary, Dr. Westring opined: (1) that there is no published standard that dictates how to determine analytical thresholds; (2) ISP Lab concluded that the analysis was inconclusive with regards to Bryan Kohberger in accordance with their published standard operating procedures; and (3) based, on Dr. Westring's independent analysis, Bryan Kohberger was excluded as a potential contributor for Item 13.1.

This motion was heard by the court on April 9, 2025. The Court issued an Order on April 18, 2025, ruling that the Defendant's motion was “ DENIED as moot. ” (See page On May 9, 2025, the State sent the following proposed stipulation of facts to the defense for their consideration:
A DNA sample taken from underneath a fingernail of Madison Mogen contained a mixture of DNA from three individual contributors. Madison Mogen and Kaylee
MOTION TO AMEND WITNESS LIST AND SUPPLEMENT EXPERT DISCLOSURES 2

Goncalves were identified as two of the three contributors to the mixture. Defendant, Bryan C. Kohberger, was excluded as a contributor to the mixture.

The proposed stipulation is attached as Exhibit S-2.

A month later, on Sunday, June 8, 2025, the State emailed defense counsel regarding the proposed stipulation since the State had not received a response to the above proposal. On June 9, 2025, defense counsel informed the State that they would not agree to the stipulation so that Defendant could present testimony on the issue.

Based on the above, it appears it may now become necessary for the State to call Dr.

Westring as an expert witness in the State's case-in-chief to ensure that the jury understands the State's position that Defendant is not a contributor to the DNA mixture and also understands why the ISP lab's reported results were described as “ inconclusive. ” If the State cannot call Dr.

Westring, the jury would be left with the misperception that the State sought to suggest that Defendant could be a contributor to the DNA mixture, which has never been its intent and would raise a variety of concerns under Idaho Rule of Evidence 403. Consequently, the State respectfully seeks the Court's permission to amend the State's witness list to add Dr. Westring and to file an expert disclosure to incorporate Dr. Westring already disclosed analysis and opinions.

RESPECTFULLY SUBMITTED this 12th day of June 2025.

2224 William W. Thompson, Jr.

Prosecuting Attorney
MOTION TO AMEND WITNESS LIST AND SUPPLEMENT EXPERT DISCLOSURES 3

CERTIFICATE OF DELIVERY

I hereby certify that true and correct copies of the MOTION TO AMEND WITNESS LIST AND SUPPLEMENT EXPERT DISCLOSURES were served on the following in the manner indicated below:
Anne Taylor Mailed Attorney at Law E-filed & Served / E-mailed PO Box 2347 Faxed Coeur D Alene, ID 83816 Hand Delivered Dated this 12th day of June 2025.

MOTION TO AMEND WITNESS LIST AND SUPPLEMENT EXPERT DISCLOSURES 4

G & S

Gustav & Sons, LLC AFFIDAVIT Forensic Science Services April 5th, 2025 William W. Thompson, Jr.

Latah County Prosecuting Attorney 522 S. Adams St., Ste. 211 Moscow, Idaho 83843
RE: Case Name: Idaho v. Bryan C. Kohberger Gustav & Sons Case Number: GS2025-001 Background and Professional Qualifications
1) I hold a doctoral degree in Biology from the University of Denver. I have more than 20 years of professional experience as a forensic biologist. I have worked on hundreds, if not thousands, of cases involving complex issues pertaining to serological testing and forensic DNA analysis.

2) I have and have been qualified as an expert witness molecular biology and forensic biology in state (Pennsylvania, New Jersey, New York, North Carolina, Connecticut), and local (Superior Court of the District of Columbia) courts.

3) I am the owner and principal investigator at Gustav & Sons, LLC, a forensic science company providing consultative services to crime laboratories, law enforcement agencies, and legal officials / practitioners.

4) I am the Laboratory Director for Niagara County Sheriff's Office Forensic Laboratory an accredited forensic science laboratory in the state of New York providing testing services in forensic biology, drug chemistry, toxicology, firearms and tool marks.

5) I served as the Director for the Center for Crime and Forensics at Purdue University Northwest, with the rank of Professor of Practice in the College of Engineering and Sciences. I taught university courses at the undergraduate and post-graduate level in forensic science, including serology and the analysis of autosomal Short Tandem Repeat (STR) DNA and lineage specific (Y-STR and mitochondrial) DNA analyses.

STATE'S EXHIBIT exhibitsticker.com Page 1 of 25
S-1

CR01-24-31665

6) I served as Laboratory Director at NMS Labs, an accredited forensic science laboratory system providing testing services in forensic biology, drug chemistry, blood alcohol content, fingerprints, firearms and tool marks, and crime scene analysis.

7) I have also served as the Quality Manager, where I was responsible for maintaining the Quality Assurance program, including implementing the FBI Quality Assurance Standards for DNA Testing Laboratories (“ QAS ”), the recommendations of the Scientific Working Group on DNA Analysis Methods (“ SWGDAM "), and the recommendations of the International Society for Forensic Genetics (“ ISFG ”), and facilitating the ANAB accreditation program.

8) I have been qualified as a certified DNA assessor where I was responsible for all aspects of quality assurance and accreditation compliance, including adherence to recognized standards from ISO 17025, ASCLD / LAB Supplemental Requirements, and the FBI Quality Assurance Standards for DNA Testing Laboratories (QAS).

9) I am a member of the Biological Data Interpretation and Reporting Subcommittee for the Organization of Scientific Area Committees (OSAC). OSAC is a joint initiative of NIST and the Department of Justice to support the development and promulgation of forensic science standards and guidelines for the United States. My specific focus is the development of standards and guidelines related to forensic laboratory DNA interpretation. In this capacity, I currently serve as the Chair for the Thresholds Task Group, and I'm also a member of the leadership team for the Terminology Task Group.

10) I have served as the Serology and Trace DNA Technical Leader in the Section for Forensic Genetics at the University of Copenhagen (Denmark). Through the Department of Forensic Genetics, I have conducted training programs in DNA analysis and forensic biology for law enforcement and the legal community.

11) In connection with my professional positions in forensic science, I have conducted training programs in forensic biology, evidence handling for crime laboratories, law enforcement agencies, and legal professionals.

12) I am a member in good standing of the International Society for Forensic Genetics, the American Academy of Forensic Sciences and the American Society of Crime Laboratory Directors, and I contribute to the field of forensic biology through publication in professional peer-reviewed literature; my publications are set forth in my curriculum vitae, attached hereto as Addendum A.

13) I am the Principal Investigator in the forensic science research program at the Niagara County Sheriff's Office Forensic Laboratory. I also have productive research collaborations with a broad range of labs and / or organizations, including UC Davis, the BATFE, NFSTC, University of Denver, Center for Forensic Science, Research, and Education, among others. My research programs in forensic science are focused on some of the complex issues faced by working crime laboratories, including various aspects of forensic DNA analysis. This includes DNA recovery techniques, DNA inhibition from firearms and explosives, and the application of mathematically derived thresholds for DNA STR interpretation. Previous research activities have been funded Page 2 of 25

by the National Institute of Justice Forensic DNA Research and Development program, the Department of Defense, the National Institutes of Health and the National Science Foundation.

14) Additional experience and qualifications are provided in the attached CV.

15) As part of my professional position, I have served as an independent DNA expert in forensic biology on matters pertaining to serology / DNA testing, review of DNA discovery materials, and providing expert opinion and testimony at trial, pretrial hearings, and depositions. I am very familiar with the types of discovery materials that are produced by case-working laboratories in the course of laboratory testing.

16) As a DNA expert, I am familiar with how to bridge best-practice recommendations from professional organizations, such as the Scientific Working Group on DNA Analysis Methods (SWGDAM), and the recommendations from the International Society for Forensic Genetics (ISFG), with forensic laboratory testing procedures.

17) I was retained by the Latah County Prosecutors Office (William W. Thompson, Jr., Prosecuting Attorney) in the matter of Idaho v. Bryan C. Kohberger to review the DNA testing conducted by the Idaho State Police Forensic Services (hereafter, ISP Lab) and the computational analysis of the ISP data conducted by Cybergenetics (Pittsburgh, Pennsylvania).

18) I have reviewed the ISP laboratory report authored by analyst Jade Miller (dated February 6,
2023) in regards to the results of DNA testing of Item 13.1 (sample from body of person A, Madison Mogen). I have also been provided with, and have carefully reviewed, the discovery materials provided by Cybergenetics including the associated case file (pdf file) for TrueAllele containing the files generated during the computational analysis. Lastly, I have also reviewed the standard operating procedures and associated validation reports produced by the ISP Lab.

19) As part of my review, I have taken into consideration the applicable recommendations from SWGDAM; OSAC; the Office of the US Attorney General; the National Commission on Forensic Science and the President's Council of Advisors on Science and Technology. These documents provide recommendations for forensic casework analyses that are intended to promote rigorous, scientifically sound, and reliable forensic DNA testing and data interpretation.

Fundamentals of Human DNA Testing for Forensic Applications
20) By way of technical background, there are various validated approaches to the analysis of human biological material (serology and / or DNA) for forensic applications. This includes commercial chemistries that are used to analyze samples for the presence of biological fluids / cells (e.g. blood, semen, saliva, etc.), as applicable. In addition, other commercial chemistries are used to analyze human (male and female) autosomal / nuclear chromosomes (i.e., chromosomes other than the X or Y chromosomes), and male-specific chemistries that are used to selectively analyze the human male Y chromosome. Lastly, some samples may also be tested for mitochondrial DNA (mtDNA) sequencing, when appropriate.

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21) Following DNA extraction, using the current generation of commercial DNA quantitation kits (e.g., ABI Quantifiler ™ Trio DNA Quantification Kit, Promega's PowerQuant ™ System, Plexor® HY System, or similar) it is possible to quantify the total yield of human and Ychromosome (male specific) DNA prior to downstream DNA analysis. DNA quantitation is routinely employed by forensic testing laboratories to determine the quantity of human (and male) DNA and is required by CODIS participating laboratories. It is possible to reliably and reproducibility detect human / male DNA from only a one human cell 1 2 3.

22) In general, autosomal and Y-chromosome analyses employ comparisons of the genotypes present at Short Tandem Repeat (STR) loci to that of known DNA profile (with the exception of DNA base searches).

23) Following amplification (all DNA STR analyses), specialized genetic analysis software (e.g., GeneMapper® IDX, GeneMarker®, OSIRIS, Sequencher®, etc.) is used to analyze the detected signal that meets laboratory-predefined quality criteria for interpretability and / or reporting.

24) Using the Promega PowerPlex® Fusion System in combination with the Applied Biosystems 3130 or 3500xL Genetic Analyzer detection instrument, it is possible to reliably and reproducibility detect complete DNA profiles from approximately 100 picograms (.1ng) of DNA (approximately 17 human cells) and partial DNA profiles from 50 picograms of DNA (9 or fewer human cells), or less. This level of sensitivity makes it possible to detect and characterize human DNA from a wide variety of evidence, including touched objects4.

25) No DNA profile is considered or known to be absolutely unique to any individual human. The use of the term “ match ” in the context of DNA testing, therefore, means that two profiles (e.g., a reference profile and an evidentiary profile) cannot be distinguished from each other at the points of comparison for which genetic data are available. Different DNA typing technologies have different capabilities with respect to the power of discrimination between different humans.

Autosomal STR testing has the highest power of discrimination such that the chance that an unrelated person selected at random from the general population will “ match ” the full DNA profile from an item of evidence by coincidence is less than one in 1 in 7 trillion. Male Y-STR DNA profiles and mtDNA profiles (both called haplotypes) are shared by all paternally related males and all maternally related persons (males and females), respectively. As a result, the power of discrimination associated with YSTR and mtDNA profiles is significantly less such that the chance that an unrelated person selected at random from the general population will “ match ” the 1 Applied Biosystems (2017) Quantifiler ™™ HP and Trio DNA Quantitation Kits USER GUIDE, Publication Number 4485354 (https://tools.thermofisher.com/content/sfs/manuals/4485354.pdf) 2 Promega PowerQuant® System TECHNICAL MANUAL, Revised 1/20, TMD047 (https://www.promega.com/- /media/files/resources/protocols/technical-manuals/101/powerquant-system-technical-manual.pdf) 3 Promega Plexor® HY System for the Applied Biosystems 7500 and 7500 FAST Real-Time PCR Systems, Revised 09/17 TM293 (https://www.promega.com/-/media/files/resources/protocols/technical-manuals/0/plexor-hy-system-forthe-applied-biosystems-7500-and-7500-fast-real-time-pcr-systems-protocol.pdf? la = en) 4 PowerPlex® Fusion System for Use on the Applied Biosystems® Genetic Analyzers Technical Manual (revised 7/20) (https://www.promega.com/-/media/files/resources/protocols/technical-manuals/tmd/powerplex-fusion-systemprotocol.pdf? rev = 55bf6471c78e44549d5e49c15ef5bb6e & sc_lang = en) Page 4 of 25

full Y-STR or mtDNA haplotype from an item of evidence by coincidence is typically measured as being one in only several hundred to several thousand. As the quality of a DNA profile decreases, so too does the power of discrimination and the change of an adventitious “ match ”.

Hence, partial and / or degraded profiles should be viewed with caution.

26) Partial / Incomplete DNA profiles / haplotypes occur when genetic data are obtained for only a portion of the points of comparison that were targeted. There are several reasons why only a partial profile / haplotype might be obtained from an item of evidence. The amount of DNA recovered for testing may be “ limiting ” (i.e., trace DNA) relative to the sensitivity of the DNA profiling kit employed; the DNA may be partially degraded (i.e., chemically / environmentally broken down) and / or the user-defined interpretation criteria (e.g., basis used to identify DNA alleles) may result in an artificial loss or failure to evaluate data at some points of comparison.

The interpretation of partial profiles, therefore, must be approached with heightened caution.

27) The interpretation of DNA profile / haplotype data typically involves comparisons between known / reference profiles and questioned / evidentiary profiles. The purpose of comparing known and questioned profiles is to determine whether a profile of interest may be excluded as a potential contributor. In some cases, it may be the opinion of the analyst that the comparison is inconclusive as of complex mixtures, limited data sets, degradation, and other common factors.

28) Comparisons that result in an opinion of “ can be excluded ” or “ inconclusive ” may be reported without the need to calculate a statistical weight for the opinion, however, Likelihood Ratio calculations may be reported in these instances (and may be reported as the reciprocal = 1 / LR).

In contrast to this, a comparison that results in an opinion of “ cannot be excluded " (or other linguistic equivalent) generally requires that the significance / weight associated with a “ match ” be calculated using appropriate statistical tools. Without an estimate / indication of the weight of a " match ", the comparison is not helpful or meaningful.

29) With respect to DNA profiles / haplotypes, the statistical measure of the weight of an opinion of " cannot be excluded ” is typically based on the statistically estimated rarity of a coincidental match to the DNA profile of interest. This depends