The Power of Genetic Genealogy in Solving Cold Cases!!

 

The world of criminal investigations has been forever changed by genetic genealogy. What once seemed like something out of a science fiction novel is now a powerful method used by law enforcement agencies to solve some of the most notorious cold cases. The use of DNA to trace suspects has been around for decades, but the combination of genetic analysis and genealogical research has brought about breakthroughs that were previously unimaginable.

In this post, we will explore what genetic genealogy is, how it works, why it’s so effective, and how it has been used to crack unsolved mysteries. We’ll look at famous cases that were solved with this technique, including the Golden State Killer, and discuss the ethical considerations and controversies that surround this innovative approach to criminal justice. I tried to type this up to be as comprehensive as possible without going overboard. If there’s something that you feel I left out that would be a great addition, please, let me know!

 

So, what is genetic genealogy?

Genetic genealogy combines the power of DNA analysis with family history research. In traditional criminal investigations, law enforcement matches a suspect’s DNA to the sample found at the crime scene. However, in genetic genealogy, the focus shifts to publicly available genetic databases where individuals voluntarily upload their DNA profiles for ancestry and family tree research.

Instead of matching a perpetrator’s DNA directly, investigators can use distant relatives who share genetic markers with the criminal, building a family tree to identify a suspect. It’s a cutting-edge method that has become a game-changer in solving cold cases that have remained unsolved for years or even decades.

 

How Genetic Genealogy Works:

The process starts with collecting DNA from the crime scene. DNA samples could include a range of biological materials such as blood, saliva, hair, semen, or even skin cells left behind by the perpetrator. In some cases, DNA may be degraded or limited, making it harder to match to a suspect using traditional forensic methods.

 

Once the DNA is collected and analyzed, investigators upload the genetic profile to public genetic genealogy databases like GEDmatch and FamilyTreeDNA, among others. These platforms are typically used by individuals who want to trace their ancestry and build their family trees, and they house millions of genetic profiles that can be accessed by law enforcement. I can still remember the TV commercials even though I quit watching regular television a long time ago.

 

What makes these databases different from CODIS (the Combined DNA Index System, used for convicted offenders) is that they are publicly accessible, meaning they include the DNA of people who have voluntarily submitted their genetic profiles for genealogy purposes. GEDmatch, in particular, has gained prominence in solving cold cases due to its large and growing database.

 

The real power of genetic genealogy lies in its ability to identify distant relatives who share genetic markers with the criminal. Since most criminals are not in CODIS, this method opens up an entirely new avenue for investigation! The DNA from the crime scene is compared to profiles in the database, and though the match may not be with the perpetrator directly, it often leads to family members. Most of the time fourth cousins or even more distant relatives.

This step is crucial because it allows investigators to trace the suspect’s family tree, which can lead them to potential suspects. The distance of the genetic match depends on how widespread the genetic markers are in the family and how many people from that family have uploaded their DNA.

 

Once a genetic match is found, genealogists or investigators use that information to build a family tree. By identifying shared ancestors and tracing down generations, they can narrow down the list of possible suspects. This technique doesn’t immediately identify the criminal but instead provides law enforcement with a list of potential candidates based on genetic connections.

Using records such as public databases, census records, and family trees, investigators can identify possible family members who fit the profile of the suspect—such as their age, location, and appearance.

After narrowing down the family tree and identifying a list of possible suspects, law enforcement follows up using traditional investigative methods. This could include surveillance, interviews, and obtaining a direct DNA sample from the potential suspect.

In some cases, a warrant is obtained to legally collect the suspect's DNA for direct comparison with the evidence collected from the crime scene. If the DNA matches, the case is closed, and the suspect is arrested.

 

Why is Genetic Genealogy Effective?

One of the primary benefits of genetic genealogy is its ability to crack cold cases that have remained unsolved for years or even decades. The famous Golden State Killer case, which had been dormant for 40 years, was solved after investigators used genetic genealogy to identify Joseph DeAngelo. This case illustrates how genetic genealogy can provide breakthroughs when traditional methods fail.

Unlike traditional DNA databases like CODIS, public genealogy databases offer access to millions of profiles. These databases are growing at an exponential rate, with more and more people submitting their DNA for ancestry purposes. This gives investigators a much wider pool to search for matches, helping to solve cases that were previously thought to be unsolvable.

Even if a suspect’s DNA isn’t in the criminal database, they can still be identified through genetic relatives. This technique opens up the possibility of solving crimes based on the shared DNA between suspects and distant relatives, even if the suspect has never been involved in a crime before.

 

Notable Cases Solved Through Genetic Genealogy:

1. The Golden State Killer (Joseph James DeAngelo):

Perhaps the most famous example of genetic genealogy is the Golden State Killer case. For 40 years, the killer remained unidentified despite committing 13 murders and 50 rapes in California. In 2018, DNA from a crime scene was uploaded to GEDmatch, which led to a match with distant relatives of the killer. This breakthrough ultimately led to the identification of Joseph James DeAngelo, a former police officer, as the Golden State Killer.

 

2. Terrence Fisher (Western Australia):

Another recent case solved using genetic genealogy involves Terrence Fisher, a man linked to multiple unsolved murders in Western Australia. After investigators uploaded DNA from crime scenes to public databases, they found a match to Fisher’s distant relatives. This led to further investigation, and DNA from the scenes was confirmed to match Fisher’s genetic profile, leading to his posthumous identification as the killer.

 

3. Michelle McNamara’s Golden State Killer Investigation:

True-crime writer Michelle McNamara played a significant role in the Golden State Killer’s identification through her book, “I’ll Be Gone in the Dark.” Her research sparked renewed attention on the case, and eventually, genetic genealogy became the key tool in solving the crime.

 

Ethical Considerations and Controversies:

As genetic genealogy becomes more widely used, there are concerns about privacy. People who upload their DNA to genealogy databases might not realize that their genetic data could be accessed by law enforcement for criminal investigations. This raises important ethical questions about whether users have adequately consented to their DNA being used in this way.

Since these databases are public, there’s an ongoing debate about whether it’s ethical for law enforcement to use them to solve crimes without explicit consent from individuals who have uploaded their DNA. While platforms like GEDmatch now require users to opt in to law enforcement access, some argue that this should be more transparent.

 

Though genetic genealogy has proven effective, there is still the risk of false positives. The distant relative approach doesn’t always lead to an exact match, which means investigators must take extra care in verifying the true suspect. Further, not all genealogical research methods are equally accurate, so it’s critical to corroborate findings with traditional investigative methods.

For instance, since Terrence Fisher had already passed away, investigators couldn’t collect a direct DNA sample from him to confirm a perfect match. Instead, they relied ENTIRELY on family connections and the genetic markers shared between Fisher's relatives and the evidence from the crime scenes. This means the conclusion was based on the genetic data of family members rather than a direct, irrefutable link to the perpetrator.

While genetic genealogy has shown significant success in solving cases, it’s not flawless. The database of publicly available DNA profiles, like those in GEDmatch and FamilyTreeDNA, is constantly growing, and the accuracy of matches can vary depending on the quantity and quality of available data. It's also possible that, in the search for genetic connections, a close match to another family member could have been misinterpreted as a match to Fisher himself.

 

The use of genetic genealogy in law enforcement is still a relatively new practice, and legal challenges are likely to arise as cases involving this technique make their way through the courts. Lawmakers may introduce new regulations to ensure the ethical use of genetic data in criminal investigations.

 As the technology behind genetic genealogy continues to evolve, its role in solving crimes is expected to grow. More databases, improved accuracy, and legal frameworks will make it an even more powerful tool in solving cold cases. However, there will also be ongoing debates around privacy, consent, and the balance between the benefits of solving crimes and protecting individual rights.

 

In conclusion, genetic genealogy has changed the way we think about criminal investigations. It’s an incredibly powerful tool for solving cold cases and bringing closure to victims' families. As the technology develops and more cases are solved, we’ll likely see even more breakthroughs in the future. However, it’s essential to navigate the ethical implications carefully to ensure it’s used responsibly.

 

What do you think about the growing use of genetic genealogy in solving crimes? Is it an exciting breakthrough or a privacy concern? Share your thoughts and join the conversation in the comments below!