CHICAGO -- During the 1990s, a vicious criminal was preying on women on the South Side of Chicago. The first victim was found beaten to death in a vacant lot in 1993. Police found DNA evidence at the scene. They found DNA evidence from the same assailant in seven other murders and a rape. But they couldn't match it to anyone.
Finally, in 2000, police arrested a man who had been seen with two of the victims shortly before they died. Andre Crawford confessed, a DNA analysis implicated him, and he was ultimately charged with killing 11 women.
You could interpret that outcome as a great success for our use of DNA technology in law enforcement. Or you could interpret it as a huge, tragic failure.
Between 1993 and 2000, the years encompassing his alleged spree of rape and murder, Mr. Crawford was arrested four times. But Illinois law allows police to take DNA samples only from suspects who have been convicted. So his genetic profile never showed up in the state database, where it could have been matched to that of the killer.
Had it been taken when Mr. Crawford was picked up for felony theft in 1993, he could have been stopped after the first murder. Ten women who are now dead might be alive today.
DNA is one of the most valuable and reliable tools ever conceived for law enforcement and criminal justice. It has been used to solve a wide array of crimes that otherwise would have gone unpunished, and it has freed hundreds of people who were mistakenly convicted and even sent to Death Row. It offers vast benefits in preventing crime. But we have yet to take the obvious step to realize its potential.
As a rule, police fingerprint everyone they arrest. Those prints are kept on file, where they can be matched against those found at crime scenes. But when it comes to DNA, the cops are fighting crime with one hand tied behind their backs. The prevailing practice across the country is to take DNA samples only from people convicted of felonies. That greatly limits the number of samples in state and federal DNA databases that can yield hits.
But the U.S. Senate wants to change that policy as far as the federal government is concerned. Recently it approved a measure that would requite the collection of DNA samples from everyone arrested or detained by federal agents, and would allow some states to submit samples from their arrestees. DNA is to the 21st century what fingerprints were to the 20th. So why shouldn't it be used just as extensively?
Californians have already answered that question by saying, "No reason at all." Last year, they approved a ballot initiative requiring the collection of DNA samples from anyone convicted of a felony or certain other offenses. Starting in 2009, under the new law, every adult who is merely arrested for a felony will have to surrender his DNA.
Some civil liberties groups oppose these changes because DNA, unlike fingerprints, contains a wealth of personal information that might be misused by the government. That's not a trivial concern. But laws already contain strict provisions to ensure that DNA can be used only to identify criminals.
Critics also think it's unfair to keep the DNA of people who may be innocent. But the unfairness is minimal. You don't suffer any injury from having your genetic information on file with the cops - unless you decide to commit a crime.
In any case, the small risk of abuse has to be weighed against the huge potential benefits. The bigger the database, the more crimes will be solved, the more crimes will be prevented, and the more innocent lives will be spared.
British police now are allowed to take swabs from anyone arrested for a crime carrying a prison sentence. As a result, they now have 2.5 million genetic profiles. Our national database, by contrast, has only 2.7 million samples - even though our population is nearly five times as large as Britain's.
The result is that the British catch a lot more criminals than we do. The FBI system has gotten 16,309 hits since it began operating seven years ago. The British get 50,000 matches a year.
In recent years, DNA has shown its enormous worth in exonerating the innocent. Now we need to put it to full use catching the guilty.
Steve Chapman is a columnist for the Chicago Tribune. His column appears Mondays and Wednesdays in The Sun.