On Monday, March 24, 2025, a supervisor over the Scientific Services Bureau became aware of a notice from a DNA testing kit manufacturer indicating that a specific lot of kits were prone to intermittently poor performance with potential to cause incomplete results or profiles.

The manufacturer recommended that the Department discontinue the use of those affected kits, offering free replacements for new ones.

This letter, dated Aug. 28, 2024, was forwarded to an individual in the Sheriff’s Department Scientific Services Bureau, who is no longer employed by the Department. However, it was recently discovered that the affected kits remained in use for approximately eight months, from July 2024 through February 2025.

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 Department will re-examine existing protocols, identify potential gaps, and implement corrective measures to prevent this from occurring again.

The Scientific Services Bureau is actively assessing how many cases may have been impacted and to what degree. This issue affects not only the Sheriff’s Department but also other law enforcement agencies and the Los Angeles County District Attorney’s Office. After the assessment has been completed the Scientific Services Bureau will notify all the affected agencies. 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. To address the potential impact, the Sheriff’s Scientific Services Bureau will retest approximately 4,000 samples. In some cases, certain samples may not be able to be retested due to their limited sample size.

“We take the integrity of our criminal investigations and the reliability of our forensic testing very seriously,” said Los Angeles County Sheriff Robert G. 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.”

“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,” 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.”