SAN DIEGO -- District Attorney Bonnie Dumanis said Monday a letter is being sent to defense attorneys in San Diego County, apprising them of concerns from a toxicology lab about incorrect test results connected to some criminal cases, primarily misdemeanors.

The Southern California-based lab recently alerted San Diego County law enforcement about potential problems with a small number of toxicology test samples and test results from June and July of this year.

"When we are told of potential problems like this, we alert the defense bar and work quickly to determine the potential scope and any impact it may have on cases," Dumanis said.

Last April, the district attorney's office also sent a letter to defense attorney organizations regarding a Riverside County lab technician who admitted falsifying reports during his work at a lab in Colorado.

Also this year, Dumanis said her office reviewed dozens of taped police interviews of suspects and witnesses that a police officer withheld in several cases. Eventually, 37 tapes were identified and are being turned over to defense attorneys for evaluation.