Post
Monday, May 2, 2005; A16

THE ARREST of a suspect in connection with the serial arsons that have plagued the Washington area for more than two years coincided last week with the out-of-nowhere connection of a rape suspect in New York with a series of sexual assaults in Montgomery County more than 10 years ago. The investigative link that made both of these breakthroughs possible was DNA technology, which allowed investigators in both cases to connect physical evidence from different crime scenes to a single person with a level of certainty not imaginable under previous technology. Using the federal DNA database, which is made up of constituent state systems, authorities were able to link a man who has used multiple names in multiple jurisdictions to an array of sex crimes in New York, New Jersey and Maryland.

The law enforcement benefits of DNA are nothing new. But the continuous demonstration of its power to identify suspects, as well as its power to exclude and exonerate other suspects and convicts, raises anew the question of why so many jurisdictions still restrict what information gets entered into their databanks.

Forty states require DNA from all convicted felons, but only four add the DNA profiles of people arrested for but not yet convicted of felonies. And some jurisdictions -- including the District -- still pick and choose which felonies are serious enough to warrant inclusion even after conviction.

The objection to more aggressive compilation of databanks is rooted in civil liberties and privacy concerns. These are not trivial, and caution may have made sense at first. But these DNA profiles cannot scientifically be used for purposes other than linking a person to material found at a crime scene. Considerable experience with DNA databases has shown that concerns about privacy and abuse are far outweighed by both the value to law enforcement and the positive civil liberties benefits the databases offer.

Consider the case of Virginia, the first state to allow authorities to include those merely arrested for violent crimes to go into the database. As of Thursday, according to Paul B. Ferrara, director of the state Division of Forensic Science, the database had produced 2,675 cold hits -- that is, matches between unsolved cases and people whose DNA profiles were newly entered into the system. The databank averages about four cold hits per day. In each of these cases, the positive linkage of someone to crime scene evidence not only offers a boon to police and prosecutors but also provides significant protection for any innocent people who may have previously been suspects. Mr. Ferrara further notes that when law enforcement agencies inquire as to possible matches between a known suspect and crime scene evidence, his lab ends up excluding that suspect 25 to 30 percent of the time. Each of those cases represents a person who will not be further investigated or harassed, let alone indicted or convicted, for crimes he or she did not commit.

Scientific questions about the lab have arisen, some of them serious. But 16 years into Virginia's experiment in using DNA databases, there have been no civil liberties problems -- no leaks of people's profiles, no misuse of data for improper government purposes. By contrast, numerous people guilty of very serious crimes are in prison, and untold numbers of innocent people have been spared law enforcement scrutiny or exonerated. Under these circumstances, the question facing policymakers in many states ought to be how to protect civil liberties by expanding -- not by restricting -- the use of DNA databases.