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Advances in DNA testing give detectives new tools


WASHINGTON - For more than a decade, authorities failed to turn up enough evidence to link Derrick Todd Lee to the string of sexual assaults and killings of Louisiana women. Yet, in the end, it was a DNA test that implicated him in a way that gumshoe police work alone could not, leading to his arrest last week.

DNA testing has been common in crimes like this for nearly a decade. But researchers, led by the FBI and state crime labs, have recently pushed forensic DNA technology into new territory, enabling authorities to link suspects and crime scenes that previously would not have been connected.

The trend is unambiguous: faster, cheaper and more automated. Scientists say they believe that recent breakthroughs allowing analysts to test DNA left in random places - on chair rails, doorknobs, in fingerprints, even on cloths that have been through a washing machine - will increasingly strengthen law enforcement.

Eventually, the idea that a police officer with a portable, high-tech device could walk into a room and detect the DNA of 20 people who had been there weeks or months earlier may no longer be the stuff of science fiction, scientists say.

"Twenty years ago, we thought this DNA thing, this was it, this was the chance of a lifetime to be at the beginning of something," said Bruce Budowle, a senior scientist at the FBI lab in Quantico, Va., who helped usher the bureau into the forensic DNA era. "Now we have that chance again, and it's very exciting."

Research and robotics

Portable devices are one avenue being explored by federally funded science labs. Though years away, such technology could quickly tell a detective whether a sample at a crime scene matches that of a convicted offender whose DNA is known. Even if DNA retrieved from a crime scene did not provide a match from a database, it could provide vital information such as the race and eye and hair color of a killer.

Other labs are focusing on extracting DNA from a tiny number of cells. In the past, analysts needed a tube of blood or fluid to produce enough DNA to test. Now they need just 10 cells. Because a person can lose hundreds of thousands of cells just by brushing against a wall, DNA could be retrieved for analysis from something merely touched.

The latest evolution in DNA technology has spotlighted the idea of using robotics to separate and analyze samples and produce graphics - time-consuming tasks now done mostly by hand. FBI and state labs expect automation to ease a backlog of hundreds of thousands of cases in which DNA has yet to be tested and to eliminate problems with contamination and mishandling of evidence.

Leaps in technology are enabling labs to test DNA samples that just a few years ago would have been too degraded to analyze. In certain cases, samples that have been submerged, burned, exposed to the elements or decayed by time can now be resurrected.

In some of the most promising work in recent months, a team led by the National Institute of Standards and Technology identified the remains of nearly a dozen victims of the World Trade Center attacks that were previously unidentifiable.

"We're getting more and more information from less and less DNA," said John Butler, a project leader for forensics and human identification at the institute. "A few years ago, nobody imagined you could get a DNA profile from a fingerprint or from a doorknob. Now, that's routine in some labs."

For scientists, the rapid advance in the field of forensic DNA is a result of what many see as a confluence of two developments: the Human Genome Project, which finished mapping the genes in human DNA this year, and heightened pressure on governments to allocate more resources to fighting crime.

Together, the two developments lit a flame under a science that until two or three years ago was underfunded and underappreciated as a tool for solving crimes, scientists say.

In response to the genome project, private companies flooded the field with new equipment for the study of DNA. Public officials became intent on spending more to fight crime and lock up offenders, leading to the creation of DNA databases that many states, including Maryland, are now compiling.

"The Human Genome Project alone put a couple of billion dollars [into the field] and just fueled technology," Butler said.

In the mid-1990s, the U.S. government allocated less than $500,000 in grants yearly to private labs for researching forensic DNA. Last year, Congress put up $80 million.

Before the use of DNA, the biggest scientific breakthrough in crime-fighting came decades ago, with the advent of fingerprint mapping.

Now the technology is becoming so precise that even if a rapist wears a condom, he will leave testable DNA on the victim and at the scene, said Arthur Eisenberg, director of the DNA Identity Laboratory at the University of North Texas Health Science Center and former chairman of the FBI's DNA Advisory Board.

"It's much easier for [criminals] to obscure their fingerprints than their biological samples," Eisenberg said. "The evidence provided by DNA is so powerful."

Scientific obstacles

But there are obstacles to the quick and easy use of DNA testing, Eisenberg and others said. For one thing, hundreds or even thousands of people's DNA might be scattered at a crime scene. Separating their DNA, or proving that it did not arrive at a crime scene merely by coincidence, can be difficult.

Because human cells disperse easily and can last for some time, a doorknob could retain DNA from someone who touched it weeks earlier. Additionally, the DNA of every police officer who walked through a crime scene could show up.

"It's just as easy to contaminate a crime scene these days as collect the evidence from it," Eisenberg said.

Some police departments in Britain solved this problem recently while trying to stop a string of car thefts. They swabbed only the area under the dashboard where one would hotwire a car, on the assumption that few drivers or passengers would reach there. Their work led to the arrest of at least one suspect.

The FBI is pursuing research into how to distinguish an individual's DNA in a sample that contains the cells of many people.

"Having new technology isn't of value unless you can implement it," Budowle said. "You can't just throw it out there."

There is some disagreement about the direction in which the science should go. Budowle said he opposes spending more to develop hand-held devices for on-the-spot DNA testing. Such analysis, he contends, should be done in the controlled environment of a lab.

But officials at the National Institute of Justice, a division of the Justice Department that will provide $1 billion toward forensic DNA technology over the next five years, say that fast analysis is crucial to the successful use of forensic DNA.

Sarah Hart, the institute's director, points to the case of Lee, who volunteered a sample of his DNA on May 5, only to disappear before the results came back 2 1/2 weeks later.

"The minute they tested him he booked it," Hart said. "He got a head start, [because] he knew they would be looking for him. We want more real-time results."

Many states, though, aren't equipped to handle even the most basic DNA tests. In Maryland, a few jurisdictions such as Baltimore can test some of their own DNA samples. But most samples in Maryland are sent to a private lab out of state and analysis takes longer.

But such complications, analysts say, may soon be history.

"Cases are being solved where there were no suspects, no witnesses," Budowle said. "These successes have blown the lid off [forensic DNA testing], and everyone wants to use it.

"Could there be something in the future that will tell you which 27 people were last in a room? Maybe. If there is, well, I guess my job's been done."

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