DNA Delivers the Verdict

On the night of June 1, 1991, a Hispanic man forced his way into the home of a pregnant Austin woman, sat her down in a lighted room, looked into her eyes, and, after a few minutes of strained conversation, raped her. The assailant later tried to convince the woman to leave her husband, telling her he could be a better provider.

After the crime, while flipping through the "black book," a police portfolio containing the mug shots of sex offenders, she pointed out her assailant to investigators: Ben Salazar, a Travis County demolition worker previously convicted of a minor sex offense.

Austin police charged Salazar with the rape, relying on forensic tests to back the victim's eyewitness testimony. The most accurate, an enzyme test, found that 1 percent of Hispanic males -- including Ben Salazar -- could have committed the crime.

In 1992, Salazar was convicted of sexual assault and sentenced to 30 years in prison.

By 1997, his appeals exhausted, Salazar's freedom hinged on DNA testing, though the Travis County district attorney resisted the idea. "There's a natural tendency: Once the case is over and the appeals have been decided, you don't want to reopen it," says Clay Strange, the self-styled "DNA guy" of the Travis County DA's office.

So, like Roy Criner, Salazar turned to a private laboratory, Genescreen, to perform the tests. The results blew the case back open: Salazar was not a match. Three weeks after an emotional hearing that granted him a new trial, Salazar left prison a free man, gubernatorial pardon in hand.

George W. Bush pardoned two men that fall. The second, Houston carpenter Kevin Byrd, also used DNA evidence to gain his freedom. The pardons are part of a nationwide legal trend: Between 1993 and 1996, 28 rape and murder convictions were overturned or dismissed on the basis of DNA evidence unavailable at trial. Both prosecutors and defense attorneys believe that DNA-inspired reversals will continue. "I'm inclined to think there are more [wrongly convicted men]," says Strange.

Most of these cases depended on DNA evidence to overturn compelling but unreliable eyewitness testimony. "I think that you're going to find a lot more people like Ben Salazar who were wrongly convicted of rape because of the bad inherent nature of eyewitness testimony," says David Schulman, Salazar's lawyer.

While the tearful accusations of a rape victim might sway a jury every time, DNA tests offer something eyewitness testimony lacks -- objective certainty. Factors such as emotion, memory and outside influence can alter the perceptions of even the most level-headed witness, although only poor methodology can taint genetic testing. Consequently, the relatively new science has earned absolute faith in legal circles, even among certain prosecutors. "[DNA testing] is not 99 percent accurate, it's 100 percent accurate, when done properly," says Strange.

DNA results are so dependable that other forensic tests, like those used to convict both Salazar and Criner, are today used more sparingly, usually when DNA tests are inconclusive or impossible. According to Dr. Elizabeth Johnson, a forensic DNA scientist at a private lab in Ventura, California, and former director of the Harris County Medical Examiner's DNA lab, pre-DNA tests (such as blood typing, enzyme tests and hair comparison) "are far less discriminating by orders of ten."

DNA testing has not only rendered many forms of forensic examination useless, it has overshadowed all other types of evidence in a number of rape cases. In 1995, for example, security guard William Don Gibson was charged with an early-morning kidnapping and rape of a doughnut shop employee near Dallas. Picked out of a lineup by the victim, Gibson signed a confession to the crime after a September 1995 interrogation that lasted, according to Gibson, more than eight hours. Gibson claims he was coerced into confessing.

Few believed his claims until 1996, when Dallas County authorities released him from prison. The reason? Gibson's DNA did not match the rapist's. "DNA is a very valuable tool in finding the truth," says Strange. "It is as neutral a forensic science as I am familiar with."

Montgomery County D.A. Mike McDougal does not share Strange's unqualified enthusiasm for DNA evidence. "I think it's helpful," McDougal says of DNA testing. "I don't think it's the end-all that everybody makes it out to be."

McDougal, like many prosecutors, considers DNA almost worthless in proving innocence. To them, genetic testing is a tool that helps tie a suspect to a crime when the results match, but can never prove a subject was not at the crime scene if they don't. "We have successfully prosecuted [cases] where the DNA didn't match the defendant's," explains McDougal. "The jury was advised of that and said, 'So what?' "

-- T.R. Coleman