PHILADELPHIA (CBS) - Police recently announced that a calibration error in at least four breathalyzer machines used to determine if someone is driving under the influence could affect more than 1,100 DUI cases (see related story). Now, the District Attorney’s Office is also implementing new policies to ensure the error doesn’t happen again.

The new policies, effective immediately, include the DA’s office going through all DUI cases from September 2009 through November 2010 by hand to identify cases in which the incorrectly calibrated Breathalyzers were used.

“We will be notifying defense attorneys in charge of the cases and letting them know that their clients if they plead guilty or were found guilty can request a new trial, ” Tasha Jamerson, Director of Communications for the Philadelphia DA’s Office, said. “We are also going to be retraining our district attorneys with our office just with the issues that arise in prosecuting DUI cases. We will also having someone in our own office who will be going over the calibrations.”

The Philadelphia Police department has already identified 1,147 cases that are jeopardized by the calibration error. Jamerson says it is unclear whether additional more DUI cases could be impacted.

Reported by Cherri Gregg, KYW Newsradio