For decades, police have used breathalyzers to prove when a driver has had too much to drink.
But now, some are challenging the science behind a certain breathalyzer used for court by police departments across Tennessee.
One group claims evidence used in several DUI cases is inaccurate, and it believes a state agency is to blame.
Most DUI cases begin with a field sobriety test, but police want solid proof. So they may bring the driver back to a station where a large instrument reads their fate.
It’s called the EC/IR II, and it’s used by 132 law enforcement departments in Tennessee. But it’s up to the Tennessee Bureau of Investigation to ensure the breathalyzer works properly.
But some said what goes in doesn’t always come out with the truth.
“We’re disappointed the TBI didn’t do their homework,” said Bryan Lewis, a Nashville defense attorney.
Lewis accused the TBI of shaky science, filing a lawsuit on behalf of 14 DUI defendants. He said the breathalyzer gave them inaccurate results, which were used against them in court.
Forensic scientists calibrate breathalyzers. In Tennessee, the legal limit for driving under the influence is .08 for adults older than 21. Currently, the TBI calibrates the breathalyzers at three points: .04, .08 and .20.
But from 2005, when these breathalyzers were introduced, until 2013, the TBI only calibrated the instruments at .082, right above the legal limit. Lewis argued that left room for error. (continue reading)