The D.C. police department is scrambling to figure out what went wrong with its breath alcohol machines, causing the city to toss out mountains of evidence in drunken driving cases and creating chaos in the court system.

Earlier this month, city attorneys began reducing charges against suspected drunk drivers and tossing out breath-alcohol scores from the city's Intoxilyzer 5000 EN machines. As word leaked out, the Fenty administration issued a mass e-mail acknowledging "a potential problem with the accuracy" with the machines that had an impact on "certain DWI cases during a specific time frame."

The city is now investigating, the statement said.

"We need machines that work in order to get drunk drivers behind bars," said at-large Councilman Phil Mendelson. "The city needs to fix this quickly -- if not sooner."

When someone is suspected of drunken driving, he or she is taken to a nearby police station and asked to blow into a breath machine. The machine then is supposed to test alcohol concentration.

Under D.C. law, a person is guilty of driving while impaired if he or she shows a blood-alcohol concentration of .08 or above on the breath machines. A person with a score below .08 can still be convicted of driving under the influence, but those convictions rely on judicial discretion.

Police Chief Cathy Lanier told WRC-TV on Friday that the problems potentially could affect hundreds of cases dating back to October 2008.

Attorney Brian Wayne Brown, who defends suspected drunken drivers, said he saw city prosecutors reducing charges or dismissing evidence and even cases on Feb. 12.

Dozens of cases have been affected so far and the city had rebuffed judges' requests for an explanation, Brown said.

"It was kind of shocking," he said. "They've got a real problem over there."

Some police officers told The Examiner that that top brass kept them in the dark about the machines' accuracy problems even while drunk driving cases were routinely being dropped. On Thursday night, after The Examiner began making inquiries into the matter, a top police official sent out a copy of the Fenty administration's statement on the matter.

Police union Chair Kris Baumann said Attorney General Peter Nickles and Fenty have "basically given drunk drivers in this city a free pass."

"They need to understand the severity and the magnitude of the problem," Baumann said.

Nickles declined comment for this story.

The city's breath-alcohol machines are manufactured by Owensboro, Ky.-based CMI, Inc. The company has had struggles in other states. Last year, the Minnesota Supreme Court ordered the company to hand over the machines' programming codes to determine if there were any system-wide problems; a Kentucky appellate court ruled similarly earlier this year.

Company officials did not respond to requests for comment.