Los Angeles County has been using potentially faulty DNA test kits in criminal investigations for months.
According to the L.A. County Sheriff's Department, on Wednesday, a supervisor became aware on Monday of a notice from a DNA testing kit manufacturer indicating that a specific lot of kits was prone to poor performance with the potential to cause incomplete results.
The maker of those kits recommended that the department stop using the kits.
That letter was sent to the L.A. Sheriff's Department on Aug.28, 2024, but apparently went to an employee who was no longer employed there.
Because nobody knew about the letter, the affected kits remained in use for eight months: from July of 2024 until February of 2025.
"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 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," Luna continued in the statement. "The Sheriff's Department is working diligently to assess the impact and to prevent such situations from occurring again."
The L.A. Sheriff's Scientific Services Bureau is now assessing how many criminal cases may have been impacted by faulty DNA tests -- and to what degree.
The discovery not only impacts the L.A. Sheriff's cases, but other law enforcement agencies that use the lab -- as well as the L.A. County District Attorney's Office.
"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," L.A. 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," he continued.
The Sheriff's Department said the use of the kits may have led to "incomplete or suboptimal results but is not likely to have falsely identified any individual."
Around 4,000 samples will be retested. In some cases, samples may not be able to be retested because of their limited sample size -- which could potentially impact prosecutions.
The L.A. Sheriff's Department has launched an internal administrative investigation to understand the oversight. It says it will examine protocols, identify potential gaps and implement corrective procedures.