LA CROSSE, WI -

La Crosse County District Attorney Tim Gruenke says dozens of items are being looked at and some may impact criminal cases after an audit of the La Crosse Police Department's evidence room.

The department conducted the audit to determine whether or not any evidence was tampered with by former La Crosse Police Lieutenant Brian Thomson. He’s been charged with attempted possession of schedule II narcotic drugs without a prescription and admitted to removing drug evidence and using the drugs.

Gruenke said some number of those criminal cases will have at least some negative impact.

“Whether that means the re-opening of closed cases, lowering of the severity of charges that are pending, or complete dismissal of criminal cases is unknown at this time and will probably take months to determine the full impact of this situation,” Gruenke said in a statement.

The La Crosse Police Department and the District Attorney’s Office are still investigating any possibility of evidence being tampered with or missing.

“Although it is a frustrating and cumbersome process, we will strive to discover any issues with the evidence and then make decisions on how to handle the issue in the cases as they come up,” Gruenke said.