HPD appetite for evidence assailed
Overconsumption often left little or nothing for DNA retesting

 April 7, 2003 | Houston Chronicle

HPD appetite for evidence assailed

Overconsumption often left little or nothing for DNA retesting

 By JAMES KIMBERLY
 

The Houston Police Department crime lab, in case after case, used up more physical evidence than experts say was necessary to conduct DNA tests, saving nothing for future tests that could exonerate or identify criminals.

The crime lab's practice long bothered defense lawyers, who said it forced them to rely on the prosecution's evidence and put them at a disadvantage in criminal trials. With the reliability of the lab's work now under scrutiny, the lab's practice is even more troubling.

The overconsumption of evidence has prevented people accused of sexual assault from conducting their own tests to see if the physical evidence supports their version of events rather than their accuser's. It was a problem in the case of Josiah Sutton, the 21-year-old released from prison last month after a new DNA test excluded him as a suspect in a rape case.

"It just defies all logic," said Dr. Elizabeth Johnson, a former DNA analyst for the Harris County medical examiner's office who now works for a private laboratory. Johnson frequently works as a defense consultant and has been an outspoken critic of the HPD crime lab.

"Any competent lab could perform such a test on (much less evidence)," she said.

Defense lawyers question whether the practice was a result of incompetence or something more sinister.

"We're of an opinion on the defense bar that someone ... suggested to them to destroy the evidence so we couldn't retest," said defense attorney James Stafford of Houston. "I've never had a case from the HPD lab where they saved anything for resampling. The only thing I had to review was their notes."

It is impossible to test the DNA composition of blood, semen, skin or hair, without destroying some of the sample. To extract DNA, the biological sample must be dissolved with chemicals so completely not even chromosomes are left intact.

The disagreement comes over how much of the sample must be used to extract a usable DNA sample.

Forensic scientists said technological advances have made it possible to extract DNA from just a few hundred cells. The physical evidence collected in a typical rape case provides more than enough DNA for analysis, they said.

The most common form of evidence in a rape case is a swab -- a long, cotton-tipped stick similar to a Q-tip, that is used to pick up biological evidence from a rape victim. If the rapist ejaculated, one swab can contain more than three times the material needed to make a good DNA extraction.

A typical rape kit includes four such swabs. The HPD crime lab frequently used all four swabs in a DNA extraction.

The former crime lab director, Donald Krueger, has refused all requests for interviews on the crime lab's troubles. Houston Police spokesman Robert Hurst refused to make Bradford available for this story.

Dr. Richard Li, coordinator of the forensic science department at Sam Houston State University, said crime labs should make every effort to preserve genetic material.

"Generally speaking, the recommendation is, only consume partial stain; save the rest of the stain for future testing," Li said.

Li said that DNA evidence in criminal cases ideally would be kept for retesting as long as possible, even after the disposition of a sentence. Standards vary from crime lab to crime lab and often depend on how much storage space is available, Li said.

Dr. Tracey Dawson, assistant professor of forensic science and forensic molecular biology at George Washington University in Washington, D.C., was even more emphatic.

"Especially now with DNA exonerations, it's really important to have that evidence stored somewhere in someone's locker," Dawson said.

The HPD crime lab was shut down in December after an outside audit cited it for failing to follow scientific protocols, for having an insufficiently trained staff and for allowing working conditions that could lead to evidence contamination. Crime scene evidence is now processed at a private laboratory.

Houston police are poring over case files and forwarding to the Harris County district attorney's office any that involved physical evidence processed by the crime lab. The district attorney's office is ordering new DNA tests in cases where a defendant was convicted or pleaded guilty.

But Assistant District Attorney Marie Munier, who is leading the review, said the office has yet to come across a case where all the DNA evidence was used by the HPD crime lab and the defendant has no chance at a review. But the review is not finished, and Munier said she won't be surprised if one comes up.

Munier said prosecutors were aware of cases where all the physical evidence was used by the HPD crime lab, but did not know enough about DNA testing to suspect a problem.

"Our assumption was they had to get enough of the sample to isolate the DNA. Evidently, from what I hear, they didn't need to use entire samples. Their procedures were faulty, I suppose," Munier said.

Munier could not say what the office will do when it encounters a case where the DNA evidence is gone.

"We'll just have to cross that bridge when we come to it," she said.

The crime lab's appetite for physical evidence almost cost Josiah Sutton a shot at freedom. Sutton was released from prison March 12 after serving 4 1/2 years of a 25-year sentence for a rape he insists he did not commit.

The strongest evidence in the case against Sutton was the HPD crime lab analysis that identified him through DNA as the rapist. The crime lab used all of the swabs in the rape kit to make a DNA profile of the rapist, leaving the defense nothing to test.

Sutton was freed after the HPD crime lab's work was deemed unreliable by independent experts. Although all the swabs were destroyed, there was enough evidence on a microscope slide to allow a private lab to perform a new DNA test. That showed Sutton could not have been the rapist.

There is nothing for Harry Bellaire to test while he appeals his sexual assault conviction. Bellaire was convicted in May 2002 of sexually assaulting a woman he met at a party in December 2000.

Bellaire insisted he and the woman only engaged in a consensual oral sex act. The HPD crime lab reported finding evidence of semen in the woman's vagina, supporting her contention that she had been sexually assaulted. The crime lab consumed all of the swabs in the rape kit,

"It definitely left us in a lurch because we were unable to test swabs for ourselves," said Bellaire's attorney, Will Outlaw. "Why consistently destroy all of the evidence, all of the vaginal swabs? And they consistently do that."

There's no clear explanation for the lab's practice.

During Sutton's trial, HPD crime lab DNA analyst Christy Kim testified that it was lab policy to use all the swabs in a rape kit to test for DNA. But no such policy appears in the lab's policy manuals, and Kim would not answer questions about lab policy or her testimony when contacted by the Houston Chronicle. Likewise, Houston Police Department officials on Monday also declined to answer questions about it.

Dr. William Thompson, a University of California at Irvine criminology professor specializing in forensic science, said extracting DNA is a complex skill, but not one that should be beyond the reach of a trained DNA crime lab analyst.

"It's not as if you have to go to any secret school to learn to do these things," Thompson said. "You just have to be somebody who is intellectually aware of what you are doing."


Back