Four Decades of DNA Testing: Catching Criminals, Detecting Disease and Illuminating Ancestry

At-home testing kits are revolutionizing what we can learn about ourselves and our pasts


Charles Manson is sometimes pointed to as the ‘most consequential’ infamous murderer of recent times. The Manson murders shined a light on the cult of personality and showed how easy it is for someone with the right amount of persuasiveness and charm to be a force for horror. But those in law enforcement would not likely pick Manson as the name earning the title of ‘most consequential.’ That title would go to Colin Pitchfork, a British criminal convicted of despicable acts against two young girls. The rape and murder of 15-year-old Dawn Ashworth in July 1986, however, would propel University of Leicester professor of genetics Alec Jeffreys to a monumental breakthrough. Jeffreys had discovered patterns in DNA that could be used to tell one person from another. These patterns are so specific that the chance of them not being from the identified person is so slender as to be nigh impossible, and Pitchfork was identified using these genetic markers – the first time DNA was used to convict a killer. In short, DNA had become the smoking gun of nearly indisputable evidence in criminal cases – and remains so until this day. 

It’s hard to imagine living in a world where there wasn’t something as conclusive as DNA evidence but 1986 – despite what your teenage children might argue – wasn’t that long ago. True, DNA testing had been used before that time for paternity and even immigration cases but after 1986, criminal cases would never be the same. Some 11 years after this breakthrough, the first home DNA testing kits were sent out – a new concept where, for the first time, people could take DNA samples at home instead of going to some facility. Since 1997, millions upon millions of people around the world have had their DNA analyzed by reputable companies such as the ones listed in this database. The reasons for doing so vary but include ancestry and heritage, paternity and the proving of other biological relationships, finding lost relatives, as well as other reasons, including possible predisposition towards disease. 

And DNA science is improving exponentially. In 2018, the US Food and Drug Administration (FDA) approved the first at-home genetic testing kit for cancer. Via a saliva sample, tests are available for BRCA-1 and BRCA-2, which can help detect the possibility of a person having a higher risk of developing certain breast cancers. It’s fair to say, however, that for the majority of people the allure of DNA testing is currently still focused on heritage and ancestry. We’re all interested in where we came from and who our ancestors were. It helps us, for example, better understand our parents and grandparents – or for those who have no living relatives – helps develop a sense of identity. Home DNA tests can completely rewrite the narrative one has been told or had imagined about their ancestry. Taking these tests is incredibly simple and also incredibly cheap. Prices range from roughly US$60 to US$100 and the results are available within anywhere from 4 to 8 weeks, depending on the service you choose. There are both saliva and cheek swab collection options, and there are a variety of options for what to test for, depending on what you hope to learn. 

Americans are called the proverbial melting pot, as everyone except for native Americans, are in fact immigrants. As many know a Polish immigrant in the 1840s, for example, might have had an ‘unpronounceable’ name such as to some immigration officer who might then have arbitrarily decided to switch the family’s name from Malinowski to ‘Herman. This family today could be completely unaware or only vaguely aware that they are of Polish heritage, and discovering this fact could help unlock answers to all sorts of questions they’ve had about their past. And as we noted above, the tests are increasingly being used to shed light on health information. There is some debate as to whether knowing you are predisposed to a certain genetic condition as indicated by some genetic markers should be given as much weight as it sometimes is, but knowledge is power. And knowing something is always preferable to not knowing it. Should you discover that you are, for example, possibly predisposed to prostate cancer, small changes in your diet recommended for those with such predispositions could save you a lot of suffering in the future, and even if you don’t develop the disease, the change in diet will probably be good for you anyway.

Being able to better understand yourself is the overall goal for most in taking a test that leads to information on genealogy. And, if you use one of the more reputable companies with a large and diverse database, you may also be able to track down relatives that you were not aware of or build a family tree that is based on more than some long-gone uncle’s vague recollections. At-home DNA can show you where you came from, both in the recent past and also thousands of years back into the distant past. Entering the fifth decade of common use, DNA continues to shine a light on and uncover the journey that led to you.