More than 1,200 driving while intoxicated convictions in Harris County are invalid after a contractor was convicted of faking inspections of alcohol breath testing devices, prosecutors said.

Deetrice Wallace, a Department of Public Safety contractor, told investigators that she had falsified inspections records for the South Houston and Clute police department intoxilyzers.

Wallace was prosecuted for three counts of tampering with a governmental record and on Friday was sentenced to a year in prison.

Harris County Assistant District Attorney Terese Buess said about 1,000 defendants convicted of DWI can petition for a retrial without evidence submitted by Wallace. Some defendants had more than one case affected.

Buess said Wallace manipulated the machines instead of changing the reference sample every month, and pocketed $146,000.

From 2002 until she was arrested in October 2008, Wallace handled DPS instruments that were used to determine alcohol concentration in DWI cases for at least seven police departments, including League City, Friendswood, Webster, Seabrook, Galveston, Clute and South Houston.

Buess said Wallace signed off on about 4,000 test slips. Of those, some did not result in convictions and others were not in Harris County. Buess did not know how other counties would address the problem. The prosecutor was not optimistic about seeking 1,200 convictions again because the office will not have test results, and other evidence has been destroyed, including videotapes.

DPS officials invalidated all breath tests recorded by intoxilyzers under Wallace’s supervision because they could not pinpoint the date when her unethical behavior began.

Once contacted, the attorney of record will contact the defendant and determine if they want to try the case again. If the defendant wants a new trial, the district attorney’s office will agree to it.

The case will then start over in the court where the conviction was obtained.

Buess said some defendants who were convicted of two DWIs and a felony DWI may get a clean slate after the dust clears. She said one defendant who will be able to get a new trial was sentenced to 60 years in prison for a felony DWI.

“It’s just a massive problem that is not going to go away,” Buess said. “It’s a huge mess.”