{"id":127410,"date":"2025-09-02T14:35:08","date_gmt":"2025-09-02T14:35:08","guid":{"rendered":"https:\/\/www.newsbeep.com\/us\/127410\/"},"modified":"2025-09-02T14:35:08","modified_gmt":"2025-09-02T14:35:08","slug":"identical-twin-convicted-based-on-dna-differences-in-first-us-case-of-its-kind-us-news","status":"publish","type":"post","link":"https:\/\/www.newsbeep.com\/us\/127410\/","title":{"rendered":"Identical twin convicted based on DNA differences in first US case of its kind | US news"},"content":{"rendered":"

For the first time in the US, an identical twin has been convicted of a crime based on DNA analysis<\/a>.<\/p>\n

On 21 August, a jury found Russell Marubbio, 54, guilty of a sexual assault that occurred in Woodbridge, Virginia<\/a>, back in 1987.<\/p>\n

Virginia-based Parabon Nanolabs ran an analysis on the DNA sample found at the scene nearly four decades ago. Genealogist CeCe Moore then traced the perpetrator\u2019s family tree and seemed to hit a wall when the sample led to identical twins.<\/p>\n

Usually, that would be the end of using DNA to solve the case. Identical twins have the same DNA \u2013 almost. There are sometimes a few cells that split and evolve differently.<\/p>\n

\u201cOn average, twins will have eight of those types of differences across the whole 3 billion bases\u201d of the genome, said Ellen Greytak, director of bioinformatics at Parabon.<\/p>\n

The scientists were able to detect some of these mutations in the sample, compared to cheek swabs from the Marubbio brothers, leading to the conviction on Friday.<\/p>\n

\u201cThis landmark case marks the first successful admission and application of this specific technique in a US court to overcome challenges in DNA identification of identical twins,\u201d Amy Ashworth, commonwealth\u2019s attorney for Prince William county, Virginia, wrote<\/a> in a statement.<\/p>\n

On 19 December 1987, a 50-year-old cashier at a Chevron gas station in Woodbridge, took a bathroom break and was followed by a young man. He restrained her and sexually assaulted her at knifepoint.<\/p>\n

The assailant left semen at the crime scene, but his DNA never matched with any offenders listed in the law enforcement database known as the Combined DNA Index System (Codis).<\/p>\n

In 2019, Giannina Pinedo, a master detective with 22 years of experience, transferred the cold case to a unit in Prince William county. She began looking through unsolved cases where DNA samples were present at the crime scene, alongside Colleen Grantham, another master detective with 23 years of experience.<\/p>\n

Scientific and technological advances in DNA sequencing and genealogical databases are now yielding breakthroughs in cases that long ago went cold. The Golden State Killer, for example, was arrested in 2018 after genetic genealogy led to a suspect, Joseph James DeAngelo, who pleaded guilty in 2020.<\/p>\n

The two Virginia detectives worked with several labs in different states. They submitted the DNA evidence to Parabon in August 2022. The company put together a sketch, based on genetics, of what the perpetrator might look like \u2013 and Moore, their chief genetic genealogist, tracked down possible suspects.<\/p>\n

The detectives worked with special agents in Florida, where the Marubbio twins lived, to obtain cheek swabs from the brothers for genetic sequencing.<\/p>\n

Parabon scientists then did whole-genome sequencing to uncover the smallest genetic differences between the men.<\/p>\n

\u201cThese are somatic mutations,\u201d said Claire Glynn, professor and executive director of the Henry C Lee college of criminal justice and forensic sciences at the University of New Haven. \u201cA better word, I think, for the public is acquired mutations, where you can differentiate between identical twins.\u201d<\/p>\n

She thinks of it as similar to punctuation in a sentence. The \u201cwords\u201d don\u2019t change \u2013 the arrangements of A, T, G, and C are the same in both twins \u2013 but sometimes there are commas in one sample where another has periods.<\/p>\n

\u201cWe would see the mutations from very early on in life,\u201d Glynn said. They develop in utero, after the embryo splits in two.<\/p>\n

\u201cIn terms of the science, that\u2019s well studied and well understood,\u201d she said. \u201cThe science behind it is absolutely robust. It\u2019s simply that it\u2019s not that common that we would encounter this in cases.\u201d<\/p>\n

There was a case in Massachusetts in 2017 where a similar analysis was performed, but the judge on that case said<\/a> the evidence was not admissible.<\/p>\n

In 2022, an identical twin was convicted of sexual assault in the Netherlands using similar genetic analysis.<\/p>\n

The rare genetic differences between identical twins may not show up at every place in the genome, Parabon\u2019s Greytak said.<\/p>\n

\u201cOnly certain cells in the twin will have that mutation and other cells won\u2019t. So they\u2019re like a mosaic.\u201d<\/p>\n

The scientists employed \u201cultra-deep sequencing\u201d, looking for any differences in the twins\u2019 samples, Greytak said. \u201cIt\u2019s really a small amount, but it\u2019s a very distinctive, clear difference.\u201d<\/p>\n

Those differences matched with the semen sample left at the crime scene, and Marubbio was convicted of violent abduction and rape.<\/p>\n

\u201cOccasionally, you get these identical twin defense cases. And it used to be, they would give up,\u201d said David Kaye, professor emeritus of law at Arizona State University. \u201cThey would say, \u2018well, all right, the DNA is not going to help us.\u2019 Now, it is possible, and it will.\u201d<\/p>\n

Commercial genealogy has also expanded rapidly in recent years with the advent of inexpensive home testing and online databases. Law enforcement are permitted to search two databases, GEDMatch and FamilyTreeDNA, only among users who have opted into law enforcement use.<\/p>\n

In this case, Moore traced two second cousins back to a common ancestor in the 1860s, and then built a family tree forward.<\/p>\n

\u201cTwo of our matches were second cousins once removed to each other, and that\u2019s really optimal for us. If someone is related, but not too related, it points to just one branch of their family tree that we need to look at,\u201d she said.<\/p>\n

Moore hit an early snag when none of the people in one branch seemed to match; eventually, she realized that one of the matches had accidentally switched their DNA kit with their spouse.<\/p>\n

\u201cWhen we looked at the spouse\u2019s tree, that\u2019s where we found the connection right away. It jumped out at us,\u201d Moore said.<\/p>\n

She also looked at geographic location \u2013 someone who was reasonably close to the scene of the crime. Investigative genealogists will search for a host of records: birth, death, and marriage certificates; census entries; information from graveyards; newspaper clippings.<\/p>\n

In this case, Moore said: \u201cwe were able to find some very compelling information in high school yearbooks.\u201d<\/p>\n

Once possible suspects are identified, genealogists like Moore can inform detectives of the lead.<\/p>\n

\u201cIt\u2019s what I call a highly scientific tip,\u201d Moore said. \u201cThey still have to do their full investigation, their due diligence, just like they would if I called the tip into Crime Stoppers.\u201d<\/p>\n

Forensic investigative genetic genealogy, or Figg, \u201cgets us to a potential person of interest,\u201d Glynn said.<\/p>\n

Sometimes law enforcement will then collect DNA from the suspect surreptitiously \u2013 looking through trash, if local laws allow it; collecting dishes or utensils from restaurants; locating discarded coffee cups or cigarettes.<\/p>\n

If those samples match the crime scene DNA, then detectives move forward with the case. That often involves an arrest and a cheek swab to see if that sample also matches.<\/p>\n

The number of identical twins is \u201chigher than people usually think\u201d, Kaye said. \u201cIt\u2019s not a common situation in the criminal investigative area, but it certainly occurs. So I would expect there would be more cases,\u201d where analyses like these are performed to differentiate identical twins.<\/p>\n

And identical twins are \u201cincreasingly common because of fertility treatments\u201d, Moore said.<\/p>\n

Understanding the genetic differences between identical twins has long been a goal of researchers, Glynn said.<\/p>\n

With the Marubbio analysis, \u201cto actually have it used in court and have it accepted by the judge is a huge step forward\u201d, Moore said.<\/p>\n

These kinds of analyses are becoming more common in cold cases as well as active cases, and more law enforcement are being trained on conducting genealogical research, Glynn said.<\/p>\n

The process can be expensive \u2013 especially when the crime-scene samples were heavily degraded by time or the environment.<\/p>\n

\u201cBut it can also be moderately cost effective,\u201d Glynn said, especially compared to the resources spent on cold cases that stretch over decades.<\/p>\n

\u201cIf we invest and spend the money on these advanced methods that then identify and allow us to apprehend perpetrators of violent crimes, the impact on society \u2013 you can\u2019t put a value on that, because if a violent serial offender is apprehended, no further people can be harmed,\u201d she said.<\/p>\n","protected":false},"excerpt":{"rendered":"For the first time in the US, an identical twin has been convicted of a crime based on…\n","protected":false},"author":2,"featured_media":127411,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[50],"tags":[200,79],"class_list":{"0":"post-127410","1":"post","2":"type-post","3":"status-publish","4":"format-standard","5":"has-post-thumbnail","7":"category-genetics","8":"tag-genetics","9":"tag-science"},"_links":{"self":[{"href":"https:\/\/www.newsbeep.com\/us\/wp-json\/wp\/v2\/posts\/127410","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.newsbeep.com\/us\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.newsbeep.com\/us\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/us\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/us\/wp-json\/wp\/v2\/comments?post=127410"}],"version-history":[{"count":0,"href":"https:\/\/www.newsbeep.com\/us\/wp-json\/wp\/v2\/posts\/127410\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/us\/wp-json\/wp\/v2\/media\/127411"}],"wp:attachment":[{"href":"https:\/\/www.newsbeep.com\/us\/wp-json\/wp\/v2\/media?parent=127410"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.newsbeep.com\/us\/wp-json\/wp\/v2\/categories?post=127410"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.newsbeep.com\/us\/wp-json\/wp\/v2\/tags?post=127410"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}