Dec 21 2023

Top 10 Blog Posts of 2023

Three years after a fully virtual symposium in 2020, it’s safe to say that the 34th International Symposium on Human Identification felt like a return to normalcy. With attendance reaching near record levels, including nearly 1/3 of attendees coming for the first time, it was great to see so many of you in the fill the Hyatt Regency and Colorado Convention Center in Denver from September 18-21, 2023.

Many of you also contributed stories to the ISHI blog this year! Just like the meeting, this year’s top blog posts reflect interest in the latest DNA technologies (especially forensic investigative genetic genealogy) and techniques as well as a sense of community. Scroll below to read the top ten posts from 2023 and subscribe to the blog at the end of the post to have future ISHI posts delivered to your email! We look forward to continuing to share actionable tips, new technologies, and announcements with you in the new year!

Do Forensic Scientists Experience Trauma at Work? Unpacking What We Know About Stress, Trauma and Burnout in a “Forgotten Population”

written by Jordan Nutting, Promega

For many years, research and efforts to mitigate workplace impacts on mental health and stress in the criminal justice system have almost exclusively focused on its non-civilian members. This makes good sense. Police officers, for example, carry service weapons, might find themselves making split second life-or-death decisions and work closely with crime victims and their families. In recent years, however, research on workplace trauma and stressors has expanded to include a “forgotten population” of people who might not directly interact with violence but who still encounter its impacts—forensic scientists (1).
Forensic scientists regularly handle the artifacts and intimate details of violent, disturbing crimes, from analyzing bloodstain patterns at the scene of an assault to prepping semen-stained clothing for DNA analysis. Though these are “secondhand” encounters with traumatic events, recent research indicates that forensic professionals’ workplace duties can lead to firsthand experience with vicarious trauma (VT). Other stressors that forensic scientists face, such as testifying in court, handling an ever-increasing backlog of casework samples and needing to produce “error-free” work are less graphic, but they are intense and can cause burnout. Altogether, the impacts of stress can have both subtle and outsized impacts on forensic scientists’ mental health and the quality of their work.

Left-Handed DNA: Is That Right?

written by Ken Doyle, Promega

What does that even mean? DNA, like many organic chemicals in biology, is a chiral molecule. That is, it can exist in two structural forms that are mirror images of each other but are not superimposable (enantiomers). Just like your left and right hands are mirror images of each other, the two DNA structures are left-handed and right-handed double helices. The DNA double helix is chiral, because its building blocks (nucleotides) are chiral.
As is often the case in the real world, the story is a little more complex. DNA molecules can exist in several types of structures, both within cells and in vitro. The form common to all living organisms is a right-handed double helix, known as B-DNA. The two other common structures are Z-DNA (a left-handed double helix) and A-DNA (a right-handed double helix with other structural features that are distinct from B-DNA). Further, it’s important to note that DNA molecules such as those seen in stock images are idealized structures. In reality, Z-DNA is not a mirror image of B-DNA, and it has several other structural features, besides left-handedness, that distinguish it from B-DNA (1).

Development and Utility of Single Sperm Genetic Analysis Methods to Aid in Sexual Assault Investigations

written by Morgan Peters^1,2, Jack Ballantyne^1,3, and Erin Hanson^1,3

¹National Center for Forensic Science, University of Central Florida, Orlando, FL USA, ²Graduate Program in Chemistry, University of Central Florida, Orlando, FL USA ,³ Department of Chemistry, University of Central Florida, Orlando, FL USA

Delayed reporting of sexual assault is very common and can be detrimental to obtaining the autosomal STR (aSTR) profile from a semen donor. Following standard aSTR analysis methods, it is typically not possible to obtain a male profile when the post-coital interval reaches 48-72 hours. This is not due to the absence of sperm cells, but rather the abundance of victim epithelial cells analytically overwhelming the limited number of sperm. One common approach to address this issue is to perform Y-STR analysis in place of aSTR analysis. While Y-STRs are very useful and should not be discounted, they do not hold the same statistical weight as aSTR analysis. Our approach to addressing the issues with aSTR analysis of late reported samples is to apply a modified version of our previously established micromanipulation methodology, in which rare individual sperm cells are manually collected into lysis mix and then directly amplified – eliminating the need for a quantification step.

Announcing the New Members of the ISHI Advisory Committee

written by Tara Luther, Promega

The ISHI planning team is excited to announce the newest members of our Advisory Committee. The committee was formed to steer the content and format of the annual symposium to reflect the interests of the diverse stakeholders in the forensic science community.
As we embark on this next chapter, we first want to extend our deepest gratitude to our departing Advisory Committee members. Their dedication, insight, and invaluable contributions have been fundamental to our success and growth. The time, energy, and wisdom they have invested have left a lasting impact, and we are deeply appreciative of their efforts.
As we bid farewell to our esteemed colleagues, we also warmly welcome our new members to the Advisory Committee. Their diverse experiences, fresh perspectives, and enthusiasm are eagerly anticipated. We are excited to collaborate with them and look forward to the innovative ideas and contributions they will bring to our team.
We will be conferring with the Advisory Committee throughout the planning of the ISHI conference. Together, we will continue to strive towards our shared goals and make significant strides in our endeavors. We are thankful to both the departing members and those just joining for their commitment to excellence and for being an integral part of our journey.

‘Baby Alpha Beta’ and the Birth of Investigative Genetic Genealogy

written by Ed Humes

A baby had come into the world on November 21, 1987, the same day eighteen-year-old Tanya Van Cuylenborg most likely left it, raped, murdered and left half-naked beside a lonely country road in northern Washington State. And, three decades later, that little girl in her thin yellow blanket would also be the key to figuring out the identity of Tanya and her boyfriend Jay Cook’s killer.

DNA Identification of Missing and Unidentified US Soldiers

an interview with Suni Edson, AFDIL

The Armed Forces DNA Identification Laboratory (AFDIL) was established in 1991 as a division of the Armed Forces Medical Examiner System as the only Department of Defense forensic DNA testing laboratory for the identification of members of the US military who lost their lives during conflict.
In this interview, Laura interviews Suni Edson, who works within the Past Accounting Group at AFDIL. She shares a project that she has been working on since 2014 to identify those who perished at the Cabanatuan Prison Camp located in the Philippines during WWII. While the prisoners where allowed to keep records of those who had passed at the camp, the remains were subsequently disinterred and moved to a cemetery in Manilla, where they were unintentionally co-mingled, fixed with a formalin powder, and subjected to environmental degradation.
Suni describes the careful work being undertaken to identify the 3,000+ remains located in this cemetery as well as challenges that the team is facing, and new research being done to overcome them to return the remains to family members for a proper burial.

Enhanced Mixture Interpretation with Long-Read Sequencing

written by Jianye Ge, University of North Texas Health Science Center

Deconvoluting mixture samples is one of the most challenging problems in forensics. Efforts have been made to provide solutions regarding mixture interpretation. The probabilistic interpretation of the Short Tandem Repeat (STR) profiles can increase the number of complex mixtures that can be analyzed. A portion of complex mixture profiles, particularly for mixtures with a high number of contributors, are still being deemed uninterpretable. Novel forensic markers, such as Single Nucleotide Polymorphisms (SNPs), Insertion-Deletion (Indels), and microhaplotypes, also have been proposed to allow for better mixture deconvolution. However, these markers either have lower discrimination power compared with STRs and are not compatible with CODIS. The short-read sequencing (SRS) technologies can facilitate mixture interpretation by identifying the intra-allelic variations within STRs. Unfortunately, the limited sizes of STR markers and the short-reads limit the number of alleles that can be attained per STR.
I am always exploring new technologies that could help with forensic problems. Long-read sequencing is one technology that has become more mature recently and has been successfully used in many other biomedical research and applications. The long-read sequencing enables the detection and phasing of a large allele/region missed by short-read sequencing, which fits very well with the need for mixture interpretation.

Locating and Identifying Victims of the Tulsa Race Massacre: A Forensic Anthropological Perspective

an interview with Phoebe Stubblefield, Interim Director of the C.A. Pound Identification Lab at the University of Florida

On October 19, 2020, in a corner of what was once the African American section of the Potter’s Field in Tulsa’s Oaklawn Cemetery, a backhoe begins scraping away layer after layer of red Oklahoma earth. Workers in high-visibility vests and orange hard hats prepare to join the excavation. Phoebe Stubblefield, Interim Director of the C.A. Pound Identification Lab at the University of Florida, looks on, bearing witness to a site that could be one of the final, unmarked resting places for victims of a massacre that happened over 100 years in the past.
Phoebe was one of the original members of the Tulsa Race Riot Commission created over 20 years ago. At that time, the investigation was put on pause. Upon Mayor GT Bynum’s renewal of the investigation, Phoebe was again called in to be a part of the team locating and identifying victims of the Tulsa Race Massacre.
In this interview, Phoebe gives an overview of the investigation from a forensic anthropological perspective. She shares how the remains are being located, what they expected to find vs what they are seeing, and the process by which they are beginning to identify the remains. She also discusses the challenges the team is facing, such as locating cemetery records from the time period of the massacre and how the team is overcoming these challenges.
For more on the Tulsa Race Massacre, we invite you to watch the keynote presentation given at ISHI 33 in 2022 by DeNeen Brown, a reporter at The Washington Post.

Project Prism: Investigating Toronto’s Missing Men

an interview with Steve Smith, Detective Sergeant with the Toronto Police Service

On April 30th, 2017, Selim Esen was reported missing to the Toronto Police. On June 29th, 2017, Andrew Kinsman was reported missing to the Toronto Police. In early July 2017, the need to create a dedicated task force to investigate their disappearances was identified. The mandate of Project PRISM was to investigate these two disappearances but also keeping an open mind to three previous missing men, Skandaraj Navaratnam, Abdulbasir Faizi and Majeed Kayhan whose disappearances were investigated during Project Houston in 2013.
The team commenced what turned out to be one of the largest investigations in the history of the Toronto Police Service. During the course of the investigation, the team was successful in identifying Bruce McArthur as someone who could not be excluded in the disappearance of Andrew Kinsman. Over the next few months the team worked to develop McArthur into a person of interest and then a suspect, finally obtaining grounds to arrest him for Murder on January 17th, 2018.
The project team continued to manage the investigation consisting of one of the largest forensic investigations in Toronto’s history. More than 1800 exhibits were seized and 18,000 photographs were taken during this investigation. Searches of 100 properties utilizing cadaver detection dogs from multiple jurisdictions were conducted. The team also liaised with police services all over the world who reported possible missing person linkages to Bruce McArthur. On February 28, 2019, Bruce McArthur plead guilty to 8 counts of first degree murder.
In this interview, Steve Smith, Detective Sergeant with the Toronto Police Service discusses the case as well as lessons learned and shares tips for other agencies working larger cases and across jurisdictions. He also shares two other unique cases that have stuck with him over the years, including one that reads like a movie script.

Forensic Scientist of Note: Meet Kelly the Scientist