The Genomic Revolution Reaches the City Crime Lab

enzozo/Shutterstock.com

How will law enforcement handle the deluge of new information available from DNA?

Lisa Ziegert disappeared from the gift shop where she worked on April 15, 1992, and her body was found four days later. From then until this past Monday, her murder remained unsolved.

Then on Monday, the local district attorney’s office in Massachusetts announced the arrest of a 48-year-old man for Ziegert’s death. Among the clues that led police to him was a computer-generated “mug shot” based on DNA found at the crime scene 25 years ago. Back then, the idea of predicting a face based on DNA would have seemed like science fiction. It is still rare today, but law-enforcement officials can quite easily order up such a test from the Virginia-based company Parabon NanoLabs.

Ziegert’s case is already being touted as an example of the power of new DNA technologies to solve crimes. In many ways, it’s the perfect example to take to the media: a young female victim, an infamous murder, a 25-year-old case. It’s unclear exactly how pivotal the DNA evidence was—the district attorney said “a number of factors” contributed to narrowing down the suspects—but there will almost certainly be more cases like this involving DNA.

With the cost of sequencing rapidly falling, forensics labs have been looking for new ways to generate leads out of DNA. “The idea of looking at markers of ancestry, eye color, and hair color has been attractive for years,” says Peter Vallone, who leads the applied-genetics group at the National Institute of Standards and Technology. New ways of interpreting DNA, however, are also more reliant on algorithms that are often secret.

Forensics labs currently use a DNA-analysis technique that is decades old and limited in scope. Instead of sequencing whole genes as cutting-edge academic research labs often do, forensics labs look for something called short tandem repeats (STR). These are repeated snippets of DNA that show up in parts of the genome that do not code for genes. Forensic labs do not actually know the sequence of the STRs they test, but they can count the number of repeats at several specific locations in the genome. Count enough repeats in enough places, and the pattern is fairly unique to each person. The FBI’s Combined DNA Index System, or CODIS—the database that police run DNA samples against—currently uses 20 core STRs to make matches.

“The forensics community,” says Cydne Holt, is “very conservative, and rightly so.” Holt is the chief scientific officer of Verogen, a forensic-genomics company recently spun out of Illumina, the major U.S. manufacturer of DNA-sequencing machines. Illumina has been on a bit of spree lately, forming new ventures to expand uses of DNA sequencers—first liquid biopsiesat-home genetic tests, and now forensics.

With DNA sequencers, forensics labs could actually read the sequences of the STRs, which could help match or rule out samples in tricky cases with degraded DNA or samples mixed with DNA of multiple people. Verogen already offers a forensics kit that works with Illumina’s DNA-sequencing machines to analyze ancestry, hair color, and eye color information along with STRs. DNA sequencers are not yet used in forensics labs, though a handful of labs are currently validating them for potential future use. The California Department of Justice, for example, began validating DNA-sequencing tools about two years ago and plans to complete the process within the next year.

In general, however, there is little regulatory oversight over how law enforcement can use these new DNA tests. DNA left at a crime scene is considered abandoned material, and police can do pretty much anything they like with it and the information encoded in it. “The law still treats an abandoned single cell of genetic material the way it treats a mask abandoned by a robber,” says Erin Murphy, a professor at New York University’s law school and the author of Inside the Cell: The Dark Side of Forensic DNA. Individual crime labs validate the tests they use, but there is no agency to make sure interpretations are correct.

As DNA-analysis techniques become more sophisticated, they will also become more reliant on proprietary algorithms to interpret the DNA. The secrecy can make it hard to identify problems.

Recently, algorithms used to look at STRs have come under fire after being examined by expert witnesses. ProPublica and the The New York Times reported in September that New York City’s DNA lab stopped using two methods for analyzing degraded and mixed DNA samples after their accuracy came under question. By then, the methods had already been used in thousands of criminal cases.

Law enforcement can also use commercially available software like TrueAllele and STRmix for mixed DNA samples. The Electronic Frontier Foundation has urged courts to allow defendants to review the source code for TrueAllele. Parabon NanoLabs, which does the facial reconstruction from DNA, has not shared its algorithms either, and it has been criticized by researchers for overstating the science.

Twenty-five years ago, when Lisa Ziegert was killed, DNA evidence was just beginning to enter the criminal-justice system. It is now routine, and its uses are only expanding. There will be new ways of using DNA to solve crimes, but there may be new ways of misusing DNA, too.

X
This website uses cookies to enhance user experience and to analyze performance and traffic on our website. We also share information about your use of our site with our social media, advertising and analytics partners. Learn More / Do Not Sell My Personal Information
Accept Cookies
X
Cookie Preferences Cookie List

Do Not Sell My Personal Information

When you visit our website, we store cookies on your browser to collect information. The information collected might relate to you, your preferences or your device, and is mostly used to make the site work as you expect it to and to provide a more personalized web experience. However, you can choose not to allow certain types of cookies, which may impact your experience of the site and the services we are able to offer. Click on the different category headings to find out more and change our default settings according to your preference. You cannot opt-out of our First Party Strictly Necessary Cookies as they are deployed in order to ensure the proper functioning of our website (such as prompting the cookie banner and remembering your settings, to log into your account, to redirect you when you log out, etc.). For more information about the First and Third Party Cookies used please follow this link.

Allow All Cookies

Manage Consent Preferences

Strictly Necessary Cookies - Always Active

We do not allow you to opt-out of our certain cookies, as they are necessary to ensure the proper functioning of our website (such as prompting our cookie banner and remembering your privacy choices) and/or to monitor site performance. These cookies are not used in a way that constitutes a “sale” of your data under the CCPA. You can set your browser to block or alert you about these cookies, but some parts of the site will not work as intended if you do so. You can usually find these settings in the Options or Preferences menu of your browser. Visit www.allaboutcookies.org to learn more.

Sale of Personal Data, Targeting & Social Media Cookies

Under the California Consumer Privacy Act, you have the right to opt-out of the sale of your personal information to third parties. These cookies collect information for analytics and to personalize your experience with targeted ads. You may exercise your right to opt out of the sale of personal information by using this toggle switch. If you opt out we will not be able to offer you personalised ads and will not hand over your personal information to any third parties. Additionally, you may contact our legal department for further clarification about your rights as a California consumer by using this Exercise My Rights link

If you have enabled privacy controls on your browser (such as a plugin), we have to take that as a valid request to opt-out. Therefore we would not be able to track your activity through the web. This may affect our ability to personalize ads according to your preferences.

Targeting cookies may be set through our site by our advertising partners. They may be used by those companies to build a profile of your interests and show you relevant adverts on other sites. They do not store directly personal information, but are based on uniquely identifying your browser and internet device. If you do not allow these cookies, you will experience less targeted advertising.

Social media cookies are set by a range of social media services that we have added to the site to enable you to share our content with your friends and networks. They are capable of tracking your browser across other sites and building up a profile of your interests. This may impact the content and messages you see on other websites you visit. If you do not allow these cookies you may not be able to use or see these sharing tools.

If you want to opt out of all of our lead reports and lists, please submit a privacy request at our Do Not Sell page.

Save Settings
Cookie Preferences Cookie List

Cookie List

A cookie is a small piece of data (text file) that a website – when visited by a user – asks your browser to store on your device in order to remember information about you, such as your language preference or login information. Those cookies are set by us and called first-party cookies. We also use third-party cookies – which are cookies from a domain different than the domain of the website you are visiting – for our advertising and marketing efforts. More specifically, we use cookies and other tracking technologies for the following purposes:

Strictly Necessary Cookies

We do not allow you to opt-out of our certain cookies, as they are necessary to ensure the proper functioning of our website (such as prompting our cookie banner and remembering your privacy choices) and/or to monitor site performance. These cookies are not used in a way that constitutes a “sale” of your data under the CCPA. You can set your browser to block or alert you about these cookies, but some parts of the site will not work as intended if you do so. You can usually find these settings in the Options or Preferences menu of your browser. Visit www.allaboutcookies.org to learn more.

Functional Cookies

We do not allow you to opt-out of our certain cookies, as they are necessary to ensure the proper functioning of our website (such as prompting our cookie banner and remembering your privacy choices) and/or to monitor site performance. These cookies are not used in a way that constitutes a “sale” of your data under the CCPA. You can set your browser to block or alert you about these cookies, but some parts of the site will not work as intended if you do so. You can usually find these settings in the Options or Preferences menu of your browser. Visit www.allaboutcookies.org to learn more.

Performance Cookies

We do not allow you to opt-out of our certain cookies, as they are necessary to ensure the proper functioning of our website (such as prompting our cookie banner and remembering your privacy choices) and/or to monitor site performance. These cookies are not used in a way that constitutes a “sale” of your data under the CCPA. You can set your browser to block or alert you about these cookies, but some parts of the site will not work as intended if you do so. You can usually find these settings in the Options or Preferences menu of your browser. Visit www.allaboutcookies.org to learn more.

Sale of Personal Data

We also use cookies to personalize your experience on our websites, including by determining the most relevant content and advertisements to show you, and to monitor site traffic and performance, so that we may improve our websites and your experience. You may opt out of our use of such cookies (and the associated “sale” of your Personal Information) by using this toggle switch. You will still see some advertising, regardless of your selection. Because we do not track you across different devices, browsers and GEMG properties, your selection will take effect only on this browser, this device and this website.

Social Media Cookies

We also use cookies to personalize your experience on our websites, including by determining the most relevant content and advertisements to show you, and to monitor site traffic and performance, so that we may improve our websites and your experience. You may opt out of our use of such cookies (and the associated “sale” of your Personal Information) by using this toggle switch. You will still see some advertising, regardless of your selection. Because we do not track you across different devices, browsers and GEMG properties, your selection will take effect only on this browser, this device and this website.

Targeting Cookies

We also use cookies to personalize your experience on our websites, including by determining the most relevant content and advertisements to show you, and to monitor site traffic and performance, so that we may improve our websites and your experience. You may opt out of our use of such cookies (and the associated “sale” of your Personal Information) by using this toggle switch. You will still see some advertising, regardless of your selection. Because we do not track you across different devices, browsers and GEMG properties, your selection will take effect only on this browser, this device and this website.