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Questions About Old Blood May Have Implications for DNA

Harris County says it is running out of room to store blood in closed investigations. The district attorney is asking the attorney general to allow courts to order the destruction of old evidence. Some worry that could set a dangerous precedent.

By Maurice Chammah, The Marshall Project
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Nearly every time someone goes to trial in Houston for drunken driving, investigators collect a blood sample. The sample is tested and kept in case of appeals. After years of arrests and trials, though, the vials of blood are taking up too much space and causing a headache for the agencies that have to hold onto them long after the cases are resolved.

Harris County District Attorney Patricia Lykos is asking Attorney General Greg Abbott whether a lower court, in closed cases, can order the disposal of blood collected while investigating alcohol-related misdemeanors. But in an era of exonerations based on DNA, some defense attorneys worry the destruction of forensic evidence in those cases could set a dangerous precedent.

Lykos’ office estimates that Harris County has stored roughly 13,000 vials of blood. Blood specimens are regularly obtained for DWI cases, especially when a child passenger is involved, or when a serious injury occurs.

“We have been unable to find clear legal authority addressing the power and procedure to destroy such blood vials,” Lykos wrote.

"Storage is a finite thing, especially when you're talking about something that's a biohazard,” said Murray Newman, a former felony district court chief in Harris County. “She wants to be able to say, ‘When I was DA, I made things more efficient,’ and that's a good goal.”

The issue of destroying old evidence has long been on the minds of prosecutors, Newman said. Back in the 1990s, when Newman was a Harris County prosecutor, many cases involved video evidence, and VHS tapes would stack up. With blood, the problem is greater, since refrigerated storage space is limited, and prosecutors want to make sure that blood in current cases is not stored in a less secure refrigerator, or at room temperature.

In 1988, the attorney general’s office decided that magistrates could order items destroyed that were “of such little value that they are ‘routinely discarded as waste.'” Lykos has asked whether blood should be considered waste that could be discarded.

Newman admitted, “You don’t want to keep it around forever.”

“But if I'm a guy that got convicted of murder, and I've been proclaiming my innocence,” he added, “that’s a different story."

In the letter, Lykos noted the potentially high stakes if evidence is destroyed too soon. “The proper timing and authority for such a step is important,” she wrote, “because premature or unauthorized destruction of evidence in bad faith may constitute a violation of a defendant's due process rights.”

For Patrick McCann, a defense attorney in Houston, any destruction is worrisome, since so many exonerations come from DNA testing. In Texas, there have been 52 DNA-based exonerations, according to the National Registry of Exonerations.

“No biological evidence should ever be destroyed. Period,” McCann said. “I think it sets a bad precedent, particularly in this day of consistently and horrifically wrong lab results.”

Since a crisis in 2004 at the Houston Crime Lab made headlines, Lykos has worked to change the office's tough-on-crime reputation by establishing a post-conviction review unit, which can investigate claims of innocence.

McCann said the disposal of the blood is a step backward. 

“To destroy this evidence is an invitation to injustice,” he said

A spokesman for the attorney general’s office declined to comment until a decision is made. Abbott's office has 180 days to make a decision.

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