Six decades ago, when Francis Crick and James Watson discovered the double-helix structure of DNA -- the master genetic code forming all living things -- it was a historic breakthrough that revolutionized biology and some other sciences.
The nucleus of almost every living cell (except red blood cells) contains about six feet of microscopic DNA strands coiled into a tiny clot -- and the molecular code in one cell is exactly like the code in an individual's other cells. (Since all creatures have hundreds of billions of cells, everyone contains billions of miles of invisible DNA.)
This science advance also improved police work, because DNA provides ironclad identity evidence. If a crime scene contains any trace of residue from an attacker -- semen, blood, skin, hair, saliva or even dandruff -- it can be matched precisely to a tissue sample from an accused person.
DNA evidence has become central to thousands of crime prosecutions. It can prove absolutely that a suspect was at a crime scene -- and it likewise can exonerate innocent defendants wrongly accused through mistaken identity. Across America, multitudes of men accused of rape through erroneous eyewitness identification have been cleared when their DNA didn't match a rapist's residue.
Already, the FBI manages a national database containing DNA data from about 12 million arrested Americans, which is used for rapid identification. In 1995, West Virginia's Legislature mandated that samples from this state's imprisoned felons must be added to the U.S. pool. A national group, DNA Saves, wants West Virginia to join 26 other states that now collect samples from every arrested person. That sounds like a solid step for law enforcement.
Last week, the U.S. Supreme Court validated this system. It ruled that police everywhere may extract DNA samples from violent suspects, to be preserved in databanks in the same manner that fingerprints are. Bravo. We think this will help guarantee that justice is accurate.
The case involved a Maryland law requiring police to take a cheek swab from each violent suspect. It was done with a man charged with brandishing a shotgun -- and his sample matched a DNA record from a previous unsolved rape. He was convicted of the rape, but appealed on grounds that his privacy had been invaded unjustly.
A Maryland court agreed with him -- but the nation's highest court narrowly ruled last week that cheek-swabbing is akin to fingerprinting suspects or photographing them, two standard police steps for identification.
"The only difference between DNA analysis and fingerprint databases is the unparalleled accuracy DNA provides," Justice Anthony Kennedy wrote.
We agree with Justice Samuel Alito, who called the issue "perhaps the most important criminal procedure case that his court has heard in decades." He added that "lots of murders, lots of rapes ... can be solved using this new technology that involves a very minimal intrusion on personal privacy."America needs fair, accurate justice. Keeping extensive DNA databases will help achieve that goal.