FORCE in Focus: Tracking SNP Panel Developments for Our Summer Data Summary

One of my personal goals for my summer “sabbatical” is to finish drafting an inter-laboratory study that—I'm embarrassed to admit—was presented more than two years ago. For whatever reason, this paper always got backburnered on my to-do list. And frankly, now I have no excuse but to get it done. So what am I doing now? Procrastinating just a tiny bit more with this blog post? No, definitely not! In order to gain inspiration and knowledge in preparation for this writing effort, I've done a literature review of the papers that have put the FORCE into action. And now that I have a blog, I've decided to put that information into a nice, tidy package in the form of a blog post.

For those who don't know what THE FORCE is, other than a form of Jedi superpower, below is a summary of the FORCE panel research development—from inception to methodological advances and case studies. I hope you enjoy learning more about the FORCE!

The FORCE Panel

This diagram represents the 5,422 SNPs in the FORCE panel, grouped into six functional categories and showing the few markers shared between them. Surrounding the central hexagon are six “petals,” each labeled with the number of SNPs in that category. Two overlap regions indicate SNPs that serve dual roles.

1. FORCE Panel Inception (Tillmar et al. 2021)

When my coauthors and I published the FORCE panel in 2021, we set out to resolve a familiar headache in forensic genetics: the need to run separate assays for kinship, ancestry, phenotype and sex-chromosome analysis. Instead of juggling multiple kits, we consolidated 5,422 SNPs into a single myBaits hybridization-capture and Next-Generation Sequencing (NGS) / Massively Parallel Sequencing (MPS) workflow. The panel combined ~4,000 autosomal markers to predict kinship from close and distant relatives (up to fifth-degree relatives, such as first cousins twice removed). It also included dozens of X- and Y-SNPs, plus smaller sets of identity, ancestry, and phenotype-informative SNPs—all carefully chosen to avoid any medically informative positions. In our proof-of-concept experiments, high-quality control DNA samples yielded 99 percent of FORCE targets with concordance above 99.9 percent when compared to microarray genotypes. Even degraded World War II bone samples produced roughly 44 percent of the FORCE SNPs using forensic genotyping thresholds, supporting even distant relationship predictions when comparing the expected relationship versus unrelated. By striving for maximum informativeness with a privacy-forward, cost-effective design, the FORCE panel provided a novel, robust assay for both reference-quality known and challenging unknown forensic samples.

2. Streamlined Amplicon Workflow (Staadig et al. 2023)

Realizing that many forensic laboratories would welcome a simpler, faster NGS/MPS workflow than hybridization-capture, Staadig et al. revisited the FORCE in 2023 with a QIAseq amplicon-plus-UMI protocol. Rather than hybridizing DNA with tens of thousands of baits in an overnight incubation procedure, the QIAseq approach adds unique molecular index (UMI) identifiers to each template DNA molecule for NGS/MPS library prep in a single-day laboratory workflow. The QIAseq approach was very effective: at inputs as low as 250 picograms (pg), SNP genotyping accuracy was above 99.9 percent, and the streamlined single-primer extension plus magnetic-bead clean-ups slashed hands-on time. For labs processing dozens of casework samples weekly—often under tight deadlines—this target enrichment alternative made the FORCE panel more accessible.

3. Disaster Victim Identification Benchmark (Gettings et al. JFS 2024)

In our 2024 paper, we put the FORCE to the test for its effectiveness relative to other SNP panels for disaster victim identification (DVI). This analysis was done as a theoretical experiment based on a true, historical disaster scenario of Kenya Air Flight 507. We benchmarked five leading SNP assays—Precision ID, Signature Prep, OmniSNP, QIAseq FORCE and ForenSeq Kintelligence HT—across hundreds of ante- and post-mortem samples. We found that while the cheapest option, Signature Prep, matched other panels’ kinship power at a steep time and cost premium, QIAseq FORCE sat squarely in the sweet spot. At roughly $200 per sample and a 42-hour extract-to-answer timeframe, it delivered robust first-degree kinship performance—making it the go-to choice for DVI teams by balancing cost, speed and reliability.

4. Non-Traditional Reference Types (Kotchey et al. 2025)

Beyond controlled validations, real-world case studies have further tested the power of the FORCE. In a recent study led by Mirna Ghemrawi and colleagues at the Center for Forensic Science Research and Education, we asked whether the panel could handle unconventional reference types—hair roots, hair shafts, and fingernail clippings—by testing them against matching buccal swab DNA profiles. The answer was yes: all sample types yielded over 99.9 percent SNP concordance with expected genotypes with high coverage uniformity. Remarkably, fingernails proved the most robust of these “non-traditional” references, recovering virtually 100 percent of SNPs. Hair roots and hair shafts—despite their higher degradation indices—still delivered 84–97 percent and 48–96 percent of loci, respectively, at high accuracy. Phenotype, ancestry, and Y-haplogroup predictions from all alternative materials matched buccal-derived results perfectly, and both MiSeq FGx and NextSeq 550 platforms produced comparable coverage and call rates. These findings underscore that when buccal swabs aren’t an option, fingernails—and even hair shafts—can serve as reliable sources for high-density SNP profiling in forensic casework.

5. Historical Case Study: “Schinderhannes” (Parson et al. 2025)

Perhaps the most interesting proof of concept came in 2025, when Walther Parson and colleagues used the FORCE to finally unmask the true identity of “Schinderhannes,” an 18th-century outlaw long thought to lie entombed in Heidelberg alongside his accomplice. Using hybridization capture, they recovered over 3,500 kinship SNPs from the remains. By comparing bone-derived DNA from skull, ribs, femur and even toe fragments to DNA from a living great-great-grandnephew’s buccal sample, the kinship inference statistics supported the expected 5th-degree relationship with high likelihood ratios (versus unrelated). Mitochondrial DNA haplotypes and phenotype-informative SNPs—predicting brown hair, brown eyes and pale-intermediate skin—aligned with historical accounts, conclusively restoring the outlaw’s name after more than two centuries.

6. The FORCE at GRC 2025

Just two weeks ago at the Gordon Research Conference on Forensic DNA in Newry, Maine, Magnus Vigeland shared an application of the FORCE to an unpublished forensic case. Magnus and his team used the AmpliSeq FORCE workflow to demonstrate how imputation, identity by descent, and X-chromosomal SNPs could provide an identification.

7. The Inter-Lab Study

Building on these innovations and applications to forensic casework, Andreas Tillmar and I are now preparing the most rigorous test of the FORCE panel yet: a multi-continental, international, inter-laboratory study that runs the same set of DNA samples through various FORCE panel target enrichment and NGS/MPS methods. These include hybridization capture, QIAseq, AmpliSeq, and xGen on both Illumina and Ion sequencing platforms. We’re evaluating genotype concordance, sensitivity, and cross-site consistency of FORCE panel SNP calls. Over the next few weeks, I’ll continue working with Andreas to write up the results of the consolidated datasets, so that by month’s end we can submit a fully polished manuscript to our coauthors for review. Our goal is simple: let the data show us how best to harness the power of the FORCE.