DNA: Putting Bad Guys Away Too

By ADAM COHEN

Debbie Smith, a receptionist in a hair salon in Williamsburg, Va., had given up hope that the police would ever catch the man who took her from her kitchen and raped her in the woods outside her home in 1989. She didn't get a good look at him during the assault, and the investigators didn't have any solid leads. For years Smith lived in fear that he would return and attack her or her daughters. But one day, her husband, a police officer, came home with good news: the state DNA lab had caught her rapist. Norman Jimmerson, in fact, was already in jail, convicted of kidnapping and robbing two other women around the same time that Smith was attacked. When his DNA was entered into the state's data bank--something Virginia law now requires of all felons--it matched a semen sample recovered from Smith and entered in the bank six years earlier. On the basis of the DNA match, Jimmerson was convicted of raping Smith and given two life sentences plus 25 years.

While DNA makes headlines by exonerating people of crimes they were convicted of years ago, the same technique is enabling police across the country to track down and put away criminals who might otherwise have gone free. DNA is the biggest thing to happen in crime solving since fingerprints--and it's likely to be a lot more useful. Fingerprints can be used only when a perpetrator happens to leave a clean imprint. But DNA can be taken from hair, sweat or saliva. It even has a convenient tendency to fall off skin, leaving genetic markers behind.

The key to harnessing the crime-busting power of DNA is building up state databases, like the one that found Smith's rapist. Forty-three states now have such databases, and they are growing rapidly. Virginia's DNA bank, for example, currently has 190,000 samples, which have produced about 60 matches so far. Those successes are likely to increase rapidly as Virginia adds 8,000 DNA samples a month.

The next big step is linking the states' databases. The FBI has started providing states with free CODIS (combined DNA index system) software, which digitizes and compares DNA profiles. This has already produced some impressive results. After a series of rapes in Sarasota, Florida investigators entered DNA from the crime scene into the national system. The DNA turned out to match that of Mark Daigle, who had served time in Virginia six years earlier for burglary. Florida officials arrested Daigle, and last year he was convicted of rape.

--With reporting by Elaine Shannon/Washington

With reporting by Elaine Shannon/Washington