About 4,000 DNA samples will be re-tested by the Los Angeles County Sheriff’s Department after receiving a warning from the testing kits’ manufacturer. Camilla Rambaldi reports for the NBC4 News at 4 p.m. on March 27, 2025.
About 4,000 DNA samples will be re-tested by the Los Angeles County Sheriff's Department after the agency discovered a letter with a warning from the testing kits' manufacturer.
The notice in a letter dated Aug. 28, 2024 from the DNA kit-maker indicated that some of the kits were "prone to intermittently poor performance" that might cause incomplete results or profiles. The manufacturer recommended the department stop using the kits and offered free replacements.
But the department only became aware of the months-old letter on Monday because it was sent to someone who was no longer with the agency, according to a news release.
"This letter, dated August 28, 2024, was forwarded to an individual in the Sheriff’s Department Scientific Services Bureau, who is no longer employed by the Department," the sheriff's department said. "However, it was recently discovered that the affected kits remained in use for approximately eight months, from July 2024 through February 2025."
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The Scientific Services Bureau is attempting to determine how many cases were affected in that eight-month window and to what degrees. After the review, the department will notify all affected agencies, the department said.
"Any given case could have one sample, could have dozens of samples all in the same case," said LASD Crime Lab Director Jim Carroll. "So, we're in the process at this very moment of mining all of the data so that we can identify the cases that could have been affected by this."
The kit manufacturer warned that the defect might have led to led to "incomplete or suboptimal results," but was not likely to have falsely identified anyone, the department said.
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"We take the integrity of our criminal investigations and the reliability of our forensic testing very seriously," said Los Angeles County Sheriff Robert Luna. "We are committed to thoroughly addressing this important issue, ensuring transparency, and taking immediate corrective action to protect the accuracy of ongoing and future cases. The Sheriff’s Department is working diligently to assess the impact and to prevent such situations from occurring again."
It was not immediately clear how long the re-tests will take. Carroll, who said all samples were stored appropriately, estimated it could be a matter of many months.
The Los Angeles County prosecutor's office said it was working with the sheriff's deparmtent to assess the situation.
"Upon learning of this issue concerning forensic testing on Monday, the District Attorney's Office has immediately started working with the Sheriff's Department to assess the scope of the situation in order to ensure that those involved in criminal justice process — defendants, defense counsel, victims, prosecutors, law enforcement, the courts and the public — are kept abreast of developments and in a position to make informed decisions on any actions that may need to take place," Los Angeles County District Attorney Nathan Hochman said. "We will follow the facts in whichever direction they take us on any individual case and make decisions that are in full accordance with the law on how to remedy any particular situation that requires such remediation. Ensuring the integrity of the criminal justice process to build and maintain trust in its outcomes is paramount as we go forward."
NBCLA reached out to DNA experts for comment.
The sheriff's department also launched an internal administrative investigation into the matter to examine protocols, potential gaps and corrective measures.
LA County Public Defender Ricardo D. García issued a statement Thursday.
"The Sheriff’s Department’s use of faulty DNA testing kits for several months impacts the integrity of the entire prosecution of a criminal case," García said. "This is a problem that has a far-reaching impact on countless pending and adjudicated cases. This kind of negligence is a violation of due process and further erodes trust in the entire criminal legal system.
"It is another stark reminder of why the death penalty can never be justified. If we cannot trust the criminal legal system to handle DNA evidence properly, we certainly cannot trust life or death decisions that come from it. Faulty DNA kits have long fueled wrongful convictions, and when the punishment is death, those mistakes can never be undone."
