A detective sits down at her desk and fires up her computer. After taking a gulp of her morning coffee, she glances over at the faded photograph with dog-eared corners pinned to the wall of her cubicle—a daily reminder that this victim is still awaiting justice and that this detective has much more work to do on a case that has haunted her for decades.
An unprecedented number of cold cases have been solved across the U.S. in the past two years—most notoriously the capture of the alleged Golden State Killer in April 2018. We’re familiar with headlines like “Cold Case Killer Captured After 30 Years Thanks to DNA Match.” This is an exciting time in the world of cold case investigations where advances in DNA testing are helping investigators break through previously impenetrable forensic DNA barriers. Investigators now have the chance to take new steps to solve cold cases that they just can’t let go—cases that were deemed unsolvable. The next question becomes, where do I begin?
Since this cutting-edge technology is new for criminal investigations, there are not many resources available to guide investigators through the process. Often detectives may have questions when trying to determine if your case is a good candidate for forensic genealogy. The best candidate cases are unsolved violent crimes, such as homicides and sexual assaults, in which no match resulted in CODIS and DNA evidence is still available for additional testing. Unidentified human remains cases are also good candidates when no direct reference or relative matches have been made in CODIS. Investigators interested in forensic genealogy have usually exhausted all other leads in the investigation and are hoping that advanced testing provides new leads that will help solve the case. Some common questions to consider:
Can the CODIS profile from my case be used for forensic genealogy?
The short answer is no. A DNA profile developed for CODIS cannot be used for forensic genealogy. A full DNA profile for CODIS contains 20 core markers—or 20 points on the human genome. When the profile is entered into CODIS, a match could be made to an offender in the database or it could link multiple cases together. In some states, CODIS can be used to attempt to identify immediate family relationships, such as parent-offspring, with a technique called familial DNA testing. However, to detect the sorts of distant genetic relationships used in genealogy, as many as hundreds of thousands of markers are needed. Measuring these markers requires new methods typically unavailable at laboratories that offer conventional CODIS testing.
Is there DNA available for my case?
Once you determine that the CODIS profile in your case resulted in no match, or that the profile cannot be used in a search, you need to track down more DNA to begin the process. In the best case, your crime lab has additional DNA remaining from previous testing that can be used. If DNA is available, request the laboratory report describing the extract and the CODIS test results. These reports have useful information to guide analysts’ decisions about additional testing. If there is no remaining extract, then you need to determine if there is remaining evidence for producing a new DNA extract. If the original evidence is consumed, perhaps there is other evidence that was not tested that may contain DNA from the unknown suspect? Most importantly, discuss this step with your lab analyst and your prosecutor. If your agency is the recipient of funding by the U.S. Department of Justice, make sure you’re in compliance with the DOJ’s interim forensic genealogy policy before proceeding. For example, the DOJ policy recommends that an attempt be made to generate a searchable CODIS profile before proceeding to forensic genealogy.
I have DNA available, now what?
If you have identified that DNA or evidence with DNA is available for additional testing in your case, congratulations! This is an important step and unfortunately many investigators find that once they go digging in their evidence room they have nothing left to test. Another question you may ask is, “How much DNA do I need?” The amount necessary depends on the lab, the type of testing, and the application. Let your crime lab folks discuss this with the private lab you choose—they enjoy talking nanograms and other forms of lab speak foreign to most cops.
Where should I send the DNA?
You’ll need to decide if you want a full-service company to work with you to have the necessary DNA testing completed and to do the subsequent genealogy work. Some law enforcement agencies are beginning to do their own in-house genealogy investigations once the DNA has been tested at a private lab. These agencies are able to upload the raw DNA file into one or more of the genealogy databases available for use by law enforcement. Most investigators, however, choose to have a professional forensic genealogist upload their DNA sample data once it has been tested at a private lab and then have that genealogist conduct the analysis. There are several companies and individuals offering forensic genealogy services around the country. Picking a partner can be a daunting task. Some labs or laboratory tests will fully consume evidence and choosing the wrong partner or laboratory test can result in permanent loss of evidence. Here are some, but certainly not all, of the things to consider when picking the right partner:
- Does the company subcontract, or does it perform testing in-house? A surprising number of companies advertising forensic genealogy either do not have a lab or do not offer the advanced testing you will need in their lab. They may outsource to one or more other vendors. Discuss this upfront to determine who is handling your DNA evidence. Likewise, do they perform genealogy research in-house or do they subcontract?
- Does the company support chain-of-custody? Has the staff testified in court? Speak with your prosecutor to determine what is appropriate for your case.
- Can the company present validation data for DNA quantity and quality requirements? Forensic DNA is often degraded or present in only minute quantities, requiring specialized methods and technology. Find out if the laboratory previously had success with forensic DNA of similar quantity and quality/degradation.
- How does the laboratory or test handle mixtures or contamination? DNA evidence from sexual assault cases often contain mixtures (for example, victim and perp). Find out if the lab and test method can accommodate this. Older cases and especially those involving bone evidence are often highly contaminated with bacteria. How does the lab handle contamination? The best labs can reduce contamination through cutting-edge DNA extraction methods and enrichment for human DNA.
Which genealogy databases allow law enforcement access?
There are multiple genealogy databases that assist law enforcement or genealogists working on behalf of law enforcement to upload unknown DNA data files to their databases. These include GEDmatch, Family Tree DNA, DNASolves.com. This list may not be exhaustive and certainly there will be more resources available in the future. At the time of writing, GEDmatch and DNASolves do not currently charge for search, however Family Tree DNA does charge to search their database.
What happens after the DNA from my case is uploaded to a genealogy database?
Your genealogist will attempt to build a family tree with the DNA data from your case. Genealogists measure relatedness using centimorgans. In the simplest terms, the more centimorgans you share with another person the more closely you are related. This portion of the process also involves traditional genealogy research utilizing public records and other database searches. While this process has been successful in dozens of cases so far, there is no guarantee that the JANE DOE or unknown suspect in your case will have a relative in a genealogy database close enough to provide an investigative lead. Fortunately, as more data becomes available, you can continue to update searches from the same DNA evidence that you have tested.
There is a lot to consider when trying to determine whether forensic genealogy is right for your case. Involve your prosecutor as well as your crime lab staff in the process and don’t be afraid to ask questions—after all, nanogram and centimorgan are not words that most cops are used to spouting during routine conversations—yet. Question private companies extensively. Keep in mind that the information provided by forensic genealogy is an investigative lead. It won’t be enough on its own to solve or successfully prosecute your case. Investigators must utilize traditional investigative methods to confirm or eliminate potential matches.
Incredible advances in forensic science—like the ability to identify suspects through a family tree or obtaining a full DNA profile from a single strand of rootless hair used to be science fiction. Today, however, the tools available to investigators are unprecedented. These advances are extraordinary—bringing justice to victims and their families by solving the coldest of cases.
