The Los Angeles County Sheriff's Department will retest about 4,000 DNA samples after discovering some exam kits used last year and in early 2025 might be prone to "intermittently poor performance," authorities said Wednesday.
The department received an Aug. 28 letter last year from the test kit manufacturer warning of these problems, but the notice "was forwarded to an individual in the Sheriff’s Department Scientific Services Bureau, who is no longer employed by the Department," according to a department statement.
That bureaucratic misstep might have caused a months-long delay in removing those potentially faulty kits.
"However, it was recently discovered that the affected kits remained in use for approximately eight months, from July 2024 through February 2025," the sheriff continued.
"In response, the Department has launched an internal administrative investigation into this matter. There are established policies, procedures, and quality assurance safeguards in place to ensure reliability and consistency of scientific results."
The sheriff’s department said the bad test kits should not have resulted in false positives to wrongly implicate an innocent person.
Based on the information provided by the DNA testing kit manufacturer, the use of the affected kits "may have led to incomplete or suboptimal results" but is not likely to have falsely identified any individual, the statement continued. "To address the potential impact, the Sheriff’s Scientific Services Bureau will retest approximately 4,000 samples."
The L.A. County Sheriff's Department, with nearly 10,000 deputies and 8,000 other employees, is the nation's largest sheriff's department.
"We take the integrity of our criminal investigations and the reliability of our forensic testing very seriously,” said Sheriff Robert Luna said in a statement. “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."
Sheriff's deputies and prosecutors from the L.A. County District Attorney's Office are reviewing cases.
“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," District Attorney Nathan Hochman said. "Ensuring the integrity of the criminal justice process to build and maintain trust in its outcomes is paramount as we go forward.”
