Forensic DNA: The Telltale Art

Forensic DNA has become a powerful tool for determining who is implicated in a crime, but its rapidly growing use poses numerous and thorny issues pertaining to privacy.


Forensic DNA: The Telltale ArtSOMETIME IN THE FUTURE, a 14-year-old cousin you never met, who lives halfway across the country, steals a candy bar from a newsstand. He is given community service and released, and the incident will be wiped from his record in several years. This minor crime, committed by someone you don’t even know, will cause your family’s DNA—and, by extension, yours—to be subjected to a computerized search every time a serious crime is committed in this country for the rest of your life.

A dark Orwellian fantasy or an all-too-likely scenario? No one can say for sure, but David Lazer ’88 argues that the advent of forensic DNA technology is changing the criminal justice system in unpredictable ways.

The use of DNA evidence has grown dramatically over the past few years, and the ramifications are startling. Forensic DNA evidence is reinventing law enforcement, giving police and attorneys an invaluable new tool for identifying perpetrators of violent crime, proving guilt or innocence. To date, more than 150 death row inmates have been exonerated due to DNA testing, and many rapists and murderers who would otherwise have remained free have been caught and convicted. The storing of personal DNA information, however, can give authorities intimate knowledge about each and every one of us, knowledge that has the potential for abuse and could trample on our right to privacy.

Lazer, associate professor of public policy at Harvard University’s Kennedy School of Government, is the editor of the just-released DNA and the Criminal Justice System: The Technology of Justice (MIT Press), a compendium of essays about the use of DNA in our criminal justice system and what it means for the future of law enforcement and civil liberties. The book evolved from a conference that Lazer organized in 2000, featuring among the speakers Supreme Court Justice Stephen Breyer, former Attorney General Janet Reno, and Nobel Prize winner James D. Watson, co-discoverer of the structure of DNA.

Lazer’s interest in the issue stemmed from a desire to study the integration of new technology into society. “I got involved in this early on in my time at the Kennedy School,” he says. “The use of DNA in the criminal justice system seemed like an opportunity to watch the system emerge and to understand how it emerged, as opposed to looking at technologies that were already in place.”

A child of two Long Island academics, Lazer considers himself “the apple that fell between the trees.” He hopes to underscore the growing importance of this issue and stimulate public debate. The principal question, in his view, is not whether we use DNA evidence but where we draw the line between individual privacy and collective security.

There is no doubt that DNA evidence has led to the capture of many criminals. Throughout the spring of 2003, for example, five rape-murders in Baton Rouge, Louisiana, went unsolved until frustrated local police investigated Derrick Todd Lee for a separate and unrelated case. When his DNA matched the DNA from the crime scenes, Lee was arrested and convicted of all five murders. In 1986, Debbie Smith was abducted from her home and raped, and spent the next nine years living in fear until police happened to enter a new prisoner’s DNA in their database. It matched the DNA taken from the crime scene. The man got life without parole, and Ms. Smith could fall asleep without worrying about her assailant still at large.

DNA evidence, says former Attorney General Reno, is “extraordinarily helpful for the immediate detection of suspects and confirmation of their guilt.” She calls it “a useful tool that prevents law enforcement from having to go down dead ends, and allows innocent people to be excluded.”

DNA technology has highlighted inadequacies in other types of evidence. Many felons who were later exonerated due to DNA evidence were convicted based on eyewitness testimony, a prosecutorial tool that has historically proved to be remarkably ineffective. Other identification tools, including hair-matching technology, fingerprinting, even confessions, are now known to be less reliable than previously thought.

As the use of DNA evidence becomes widespread, certain troubling and complex issues have evolved. Major questions surround the establishment and use of DNA databases. As of now, every state in the country has one, but they have different standards for who gets included and in what form, raising significant questions about what procedures should be established and applied. Should law enforcement officials collect DNA only from people convicted of serious crimes, or from everyone who is arrested for these crimes? Or, as some believe, should there be a universal database, with all of our identifying DNA information collected at birth?

These unresolved issues are not just theoretical; they play into the lives of real people. Police in Truro, Massachusetts, a small, rural village on Cape Cod, had been investigating the murder of journalist Christa Worthington for three years without success. They then asked the town’s male population for DNA samples since DNA evidence showed that Ms. Worthington had sex several hours before her murder, and her partner had never come forward. Instead of setting up formal procedures, however, the police simply stood in front of the town’s post office, grocery, and garbage dump requesting swab samples from men going about their normal business, making it clear to those who refused that they would be closely watched.

In response, Lazer co-wrote an op-ed for the Provincetown Banner titled “DNA Sweep Must Be Accompanied by Informed Consent” that said, “With such investigative power comes great responsibility. Without individualized suspicion and a bench warrant, contribution of DNA should be non-coercive, completely voluntary and well informed.” (A suspect in Worthington’s slaying, a 33-year-old garbage collector, was arrested April 15, 2005, on Cape Cod.)

Another troubling issue is the fate of DNA samples after they’re screened. People told their samples will be destroyed might be shocked to learn that often samples are instead placed in storage. “In most of the DNA dragnets I’m familiar with, they retained the DNA,” says Lazer. “But if you’re just a guy at the post office and they asked to swab your cheeks to help investigate this crime, you may not have meant to have your DNA searched against all crime scenes in the future. So there’s a whole set of difficult issues around what is done with your sample once they’ve collected it, and whether you consented to that.”

Aside from the clear civil liberties violations, Lazer considers the sweep method ineffective. The chance of a perpetrator contributing a sample is virtually nil, and the expense involved is not a prudent use of scarce resources. Given the backlog of more than 500,000 criminal case samples still waiting to be tested, sweeps only exacerbate the problem.

A universal database would make dragnets a thing of the past and would allow law enforcement to compare DNA evidence from a crime scene against the entire population. The benefit of this system is obvious and enormous. The chance of capturing criminals shortly after they commit their crimes would skyrocket. The number of unsolved cases could plunge, as could the number of innocent people investigated, arrested, and convicted for crimes they did not commit.

While the potential benefits of a universal DNA database are tremendous, so are the potential abuses. With the ability to test all DNA found in a location, law enforcement could conceivably track our movements. “We leave DNA various places. You can go somewhere and pick up cigarette butts or swab a water glass, and say who was in that room. Some of those DNA may be unrelated to a particular crime scene, but just because I happen to have left my DNA there, I become subject to investigation. For example, let’s say there’s a rape in a hotel room, and there is a bedspread in the room with semen stains on it. The police test the stains and get profiles. You could imagine not being involved in that crime, but that resulting investigation being a little awkward for an innocent party.”

The potential abuses of a universal database are as vast as one’s imagination. Lazer raises the specter of powerful politicians gaining access to information that should be confidential—who has illegitimate children, for instance. DNA evidence could also, if not adequately safeguarded, be used to plant biological evidence to implicate someone. “You wouldn’t want the DNA lab technicians being told, ‘Well, it would be really good for the D.A.’s political career if you found a match here’,” he says. “It’s very important to buffer those kinds of technical decisions from the political process.” To remove this from the realm of conspiracy theory, he cites the case of Frederick Zain, a West Virginia State Police forensics expert who was found to have faked a slew of evidence—including DNA evidence—during his ten years as the state’s crime lab director, leading to the convictions of hundreds of innocent people.

One function of DNA databases that may further complicate civil liberties is a process known as familial searching. When law enforcement checks DNA from a crime scene against DNA from an individual, it is possible to rule that person out as a suspect, but also notice genetic similarities indicating that the perpetrator is a relative. The technology is at an early stage, and it is still rare for familial searching to uncover a culprit. But it is not unheard of: In the U.K., a man who stabbed a prostitute to death in 1988 escaped undetected until the year 2000, when, while perusing evidence from unsolved murders, police scoured the crime scene and found specks of blood that allowed them to create a DNA profile. The DNA did not match anyone in the U.K.’s DNA database, but police did find a familial match with a boy who was in the database due to a minor auto-related crime. The police did DNA swabs on the boy’s relatives, eventually leading, in March 2003, to a confession from his uncle. When the murder occurred, the 15-year-old whose crime eventually led to the solving of the case was not yet born.

Lazer emphasized that in that case, the murderer had a very unusual genetic marker that facilitated his capture, but also says that technology should allow for much wider familial searches in the next ten or 20 years.

This could mean that even if a universal DNA database runs into legislative or other roadblocks, we can still have a de facto universal database thanks to what we can call the “Six Degrees of Separation” factor. We will eventually have enough people in the database for each of us to have at least one distant relative there. Through the use of familial searching, that will leave every one of us open to investigation, whether we’re in the database or not.

“Two trends will come together,” Lazer says. “One is that the database size will go up and up. Right now, we have two million people in the database, from some states where you have virtually no one, to states like Virginia, which has about one in 15 men. But the capacities are growing enormously. The second trend is that it is getting much cheaper to analyze DNA. In future years, we’ll be able to extract magnitudes more genetic information from samples than we can now. In ten, 20 years, it will not be difficult to go beyond first-degree relatives—siblings, parents, and children—to uncles and aunts and cousins and the like.”

While civil libertarians are bristling at the prospect of this type of perpetual surveillance—the ACLU, for example, has lobbied hard for the government to only store DNA from violent convicted felons—Frederick R. Bieber, a professor of pathology at Harvard Medical School and Lazer’s op-ed co-author, argues that failure to use every crime-fighting tool available raises ethical questions of its own. “It’s hard to look a victim or victim’s family in the face and say, ‘We could have prevented your daughter’s rape and murder had we done familial searching, but instead we ignored a tool that could have found the perpetrator.’ It’s unconscionable.”

Christopher Asplen, former director (under Attorney General Reno) of the National Commission on the Future of DNA Evidence and the man who recruited Lazer to coordinate the 2000 conference, believes that much of the controversy will be irrelevant, since many of the objectionable aspects of universal databases are already part of our society.

“We already take biological samples and do genetic testing of all babies at birth,” Asplen points out. “Clearly, in every state in the country, the cost benefit and legal analyses have determined that it is appropriate, it is in the public good, to take DNA from newborn children to make sure they don’t have certain diseases.” Asplen also cites footprints taken at birth of an example of how unique identifiers are already kept on every American citizen. “That footprint is exactly the same as a forensic DNA profile. You can’t tell anything else about the person other than for identification purposes. If we understand what a forensic DNA profile is, and what’s contained therein, the analogy to a footprint we take when a child is born is pretty easy to make.”

Which brings up the unresolved matter of exactly what DNA samples are kept. A biological sample—that is, taking a blood sample or DNA swab and keeping it—unlocks much of the personal information that people think of when they think of DNA. But forensic DNA databases examine “a very limited part of the DNA,” one that only serves to identify us, not to reveal our innermost biological secrets. “In the U.S., we only look at 13 areas of the DNA, and they were selected because they can’t tell us things like skin color, predisposition to disease, etc.,” says Asplen. “Once you’ve identified those, the profiles are digitized and put into a computer. So the only things in a DNA database are digitized representations, just numbers. If you then destroy that swath of blood, it’s gone. You can’t go back and test for other factors.” He believes that universal databases are inevitable, but that original samples should be destroyed.

To prevent widespread abuse of DNA technology, Lazer believes that society must be fully engaged in the discussion. “It’s a balancing act, and we have choices to make. We have the technical capacity to do things we couldn’t do a generation ago, but just because we have the capacity doesn’t mean we should do it. We may decide to constrain our capacity for familial searching, for example, saying we’ll only do it in serious cases. For murders, we’ll do familial searching, but on other cases we won’t. There are certain scenarios where I think most would agree we should pull out all the stops. If you’re investigating the possibility of a nuclear bomb in Manhattan, then you might be a little bit more aggressive.”

In the coming years, how DNA is used and managed is an issue that will affect us all, and Lazer hopes to move the discussion forward. “We have a set of choices around the use of DNA in the criminal justice system, and they pose different balances between individual rights and society’s interest in security. I think we need to seriously engage the issue of exactly where we want to strike that balance. If I had to put out a 40,000-foot message to the general public, that is the message: People have to understand that DNA has the potential to solve many crimes, but that it can also reveal things about people who haven’t committed crimes.”

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