Partners in Crime: How DNA and Family Trees Are Solving Major Cases
CSI, Bones, Criminal Minds. You name it, we binge it.
We’ve all seen crime dramas on TV and fallen in love with the sassy detectives and quirky lab techs. We’re fascinated by the fast-paced and exciting world of forensic science.
True Crime
The reality is, however, that crimes aren’t solved in a day or two like they are on TV. It can take days, weeks, or even months to process fingerprints, DNA, and other evidence collected from a crime scene. After that, detectives could still end up working on a case for years before catching the culprit. If they ever catch them.
The problem stems in part from the fact that the database used in the criminal justice system, CODIS or Combined DNA Index System, only contains DNA profiles from known convicted offenders, not any random Joe Shmoe off the street. If law enforcement officials have a DNA sample from a crime scene but there aren’t any matches in CODIS, they’re no closer to catching the criminal than if there weren’t any forensic evidence at all. So Joe Shmoe gets away with it!
How can we fix this glaring problem and bring more criminals to justice?
Recently, detectives working on a 44 year old cold case decided to try a new method of tracking down criminals.
The Golden State Killer
The Golden State Killer terrorized 10 counties in California from 1974 to 1986 with a long string of murders, rapes, and burglaries. The cops at the time had no way to identify the suspect and he got away with it for years.
The crimes weren’t all connected to the same suspect until 2001, more than twenty years later. One man could be tied to more than 100 crimes, but there was no way to figure out whodunit.
Detective Paul Holes, who had been working on the case for 24 years, had an idea.
Calling All Available Resources
Why not use current genealogical methods in the investigation?
Genealogy companies like Ancestry and 23andMe sell DNA kits where people can send in their DNA samples and then connect to their relatives based on DNA matches. One problem, however, was that each company had its own DNA database and members of one company’s database couldn’t match profiles with anybody whose DNA was in another company’s database.
GEDmatch changed all that.
GEDmatch is a database where people can share their DNA profiles from any company to further DNA and genealogical research. Anyone can submit their DNA to GEDmatch and once it’s on the site, members can view, search, and compare their DNA profiles.
Detectives Turned Genealogists
Detective Holes got permission to submit the DNA from the Golden State Killer case to GEDmatch.
He found matches.
The profiles that matched the suspect’s DNA were distant relatives of the suspect, probably third cousins. It was the biggest break in the case they’d ever had.
The detectives started building a family tree from the closest common ancestors of the DNA matches: great-great-grandparents from the 1800's. They worked tirelessly using common genealogical resources like birth, death, and marriage certificates to create an enormous family tree. Then, they whittled down the list to people who lived in California at the time of the murders and came up with just two suspects.
After ruling out a suspect through a DNA test of a close relative, only one suspect was left: Joseph James DeAngelo.
Now they had to prove it was him.
The cops surveilled DeAngelo and took a DNA sample from a piece of discarded trash, most likely a used paper cup or napkin. The sample was processed and it matched the crime scene DNA samples. Joseph James DeAngelo was the Golden State Killer. They’d caught the culprit after forty-four long years of investigation by doing the man’s genealogy.
Genetic Genealogy in the Spotlight
The success of using DNA and genealogy in the Golden State Killer case spotlighted a branch of genealogy called genetic genealogy. Most of us have an understanding of genetics and genealogy as separate topics, but how are they related?
Genetic genealogy uses DNA testing to help create family trees. DNA profiles help genealogists determine a person’s ethnicity and their relationship to another person solely based on DNA. Genealogists use that base information to build a family tree connecting matching DNA profiles by using traditional genealogical research methods. For example, genealogists use DNA in adoption and unknown parentage cases to create a complete family tree when the paper trail has gone cold.
Today, law enforcement officials, lab techs, and genealogists are teaming up to solve major crimes and cold cases because they’ve seen how effective genetic genealogy can be.
The Future of Crime Solving
There are DNA labs and professional genealogists dedicated to developing the field of genetic genealogy and applying it to forensic science and criminal justice.
Parabon Nanolabs is a DNA technology company that provides forensic DNA services and products. They are a major proponent of the field of genetic genealogy. Parabon offers their lab services to law enforcement by analyzing DNA samples from crime scenes and uploading them to GEDmatch.
CeCe Moore is a professional genetic genealogist. She founded the Institute for Genetic Genealogy and recently started working with Parabon, where she leads the Genetic Genealogy Services unit and works with law enforcement to solve crimes. CeCe Moore and other genetic genealogists are an invaluable resource in using DNA analysis and genealogy to track down a suspect. Whereas Detective Holes and his team spent months building family trees connecting the suspect to the relative matches, CeCe Moore can do it in a fraction of the time due to years of genealogical experience.
GEDmatch Controversy
When the story of the Golden State Killer case broke, many GEDmatch users began to worry about their privacy. Is it legal for the police and genetic genealogists like CeCe Moore to sift through their DNA without permission?
Normally, law enforcement officers must obtain a warrant from a judge stating that they have probable cause to obtain DNA samples from relatives of suspects. In this case, however, the detectives had free access to the DNA profiles of DeAngelo’s relatives.
GEDmatch, in its Site Policy, states that “genealogy research requires the exchange of information” and that any and all genealogy data uploaded to GEDmatch can be viewed and shared by other GEDmatch users. The company updated the Site Policy in May 2018 to explicitly state that law enforcement can use GEDmatch to “identify a perpetrator of a violent crime against another individual or identify remains of a deceased individual.”
Despite the controversy surrounding law enforcement’s use of GEDmatch in crime solving, the number of people uploading their DNA profiles to GEDmatch has actually increased since the Golden State Killer was caught. It seems that most people are okay with and even encourage law enforcement to access their DNA profiles.
Why? The larger the DNA profile “gene pool,” the more crimes that can be solved. Detectives are no longer limited in their investigations by the shallow puddle of DNA profiles CODIS contains.
Admit it — we all secretly want to be detectives or CSI’s like the characters in our favorite crime shows. But what if we actually could contribute to real criminal investigations? If we bought a DNA kit from Ancestry or 23andMe and upload it to GEDmatch, we’d be helping solve major crimes like the Golden State Killer case. We can keep the world a safer place without having to become cops or FBI agents.
So buy a kit to support your local sheriff! Unless you’re a criminal... In that case, just turn yourself in because soon there’ll be nowhere to hide with the genetic genealogists on the case.
