Crime lab fires investigator after alleged violation

Officials say she used unapproved device that botched at least 2 sexual assault cases

The Houston Forensic Science Center has fired a crime scene investigator who violated policy by using unapproved equipment that resulted in false negatives for biological evidence in at least two sexual assault cases, officials said Friday.

Lab officials, who fired investigator Tammy Barette on Thursday, said they may never know the full impact her actions may have had on other cases.

“When protocol is violated, incidents like this occur and HFSC cannot tolerate such conduct,” said Peter Stout, CEO of the forensic science center. “The work done by HFSC has enormous impacts on people’s lives, the justice system and the community. We take that responsibility seriously and believe we have an obligation to hold ourselves to the highest standards.”

Barette, who has been with the agency since 2015, could not be reached for comment.

As a crime scene investigator, Barette was required to use a device called an Alternative Light Source, which identifies the presence of biological fluids such as blood, saliva and semen. The tool doesn’t prove the presence of DNA or involve the actual testing of the material, Stout said.

But Barette was using her own instrument, which didn’t meet the forensic science center’s requirements, officials said Friday. Adequate light sources need to operate at a range of wavelengths, and the investigator’s operated on only one.

Tyler Flood, criminal defense attorney and former president of Harris County Criminal Lawyers Association, commended the crime lab for being transparent and called the investigator’s alleged actions a “complete disregard for the integrity of forensic evidence.”

“These written standard operating procedures are what allows these labs to do what they do,” Flood said. “That wasn’t be-

ing done here.”

A supervisor first discovered that Barette was using her own equipment during a routine technical review for quality control. He noticed she hadn’t documented testing the light source before working with case materials, which is required, Stout said.

Out of 19 cases in which Barette used the improper light source, including the case that sparked the investigation, only four had evidence available to retest, agency spokeswoman Ramit Plushnick-Masti said. Two of those were wrongfully marked as negative for the presence of biological fluids, when they should have yielded positives.

In the 15 cases that were unable to be tested because of a lack of evidence, Stout acknowledged the possibility that some of those could have had a different outcome. The forensic science center was unable to immediately provide the span of cases that weren’t tested, but Plushnick-Masti said that the crime scene unit almost exclusively responds to violent crime scenes, including homicides, aggravated assaults and sexual assaults.

No charges have yet been filed in the two cases that yielded incorrect results from the light source, and the updated results will be sent to prosecutors, Stout said. It’s yet to be seen whether the findings will have an impact.

Stout said the forensic agency had other issues with the Barette regarding policies and procedures, none of which affected her casework until the recent incident.

“Certainly we will continue to emphasize the necessity of following policies and protocols,” Stout said. “Is our training adequate? We’re not seeing anything that says we need to change the policies and procedures.”

During the investigation, the center strengthened the language of a policy to make it clear that unauthorized equipment was not allowed, Plushnick-Masti said. And in their case notes, investigators must now write down the exact model number of their instruments.

The firing is just the latest trouble for the crime lab, which fired an analyst in January after it was discovered that she shredded original case notes from a homicide. And in April 2017, it was reported that 65 criminal cases were jeopardized because of errors by Houston crimescene investigators, including 26 homicides, five officer-involved shootings and six child deaths.

The Harris County District Attorney’s Office has been notified about the most recent firing, and the forensic science center will notify the Texas Forensic Science Commission, a state oversight board. The district attorney’s office declined to comment.

“The work done by HFSC has enormous impacts on people’s lives, the justice system and the community. We take that responsibility seriously and believe we have an obligation to hold ourselves to the highest standards.”

Peter Stout, CEO of the forensic science center