TRENTON -- A grand jury indicted a State Police officer for purposely, improperly recalibrating a device used by police to obtain a blood alcohol level, an alleged offense that could impact 20,000 DWI cases. reported that Sgt. Marc Dennis faces charges of second-degree official misconduct, third-degree tampering with public records and fourth-degree falsifying records.

The trooper is the subject of a federal class-action lawsuit that seeks to throw out thousands of DWI convictions in New Jersey, after he was accused of botching the calibration of breathalyzers police use on suspected drunk drivers by deliberately omitting a temperature check when re-calibrating Alcotest devices.

The complaint says BAC readings from breathalyzer tests have been thrown into question after the state Attorney General’s office charged Dennis with records tampering, alleging he skipped a critical step in the required six-month recalibration of all Alcotest instruments manufactured by Draeger Safety Diagnostics. Dennis has denied wrongdoing.

According to, Dennis was found to have skipped this step only three times, enough to throw into doubt 20,000 DWI cases that used machines he calibrated.

Contact reporter Dan Alexander at

More from New Jersey 101.5: