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 ...

The manufacturer of the test kits notified the Los Angeles County Sheriff’s Department in August that many of the kits were likely defective, but it kept using them for several months.

FILE - A roll of police tape is left on the windshield of Los Angeles County sheriff's vehicle in the parking lot of its training academy in Whittier, Calif., Wednesday, Nov. 16, 2022.