To prove a DUI charge, prosecutors normally need to show that the driver was actually impaired by alcohol or had a blood alcohol concentration (BAC) of .08% or more (a “per se” DUI). An accurate BAC measurement is critical for a per se DUI conviction. And a high BAC can also provide evidence of driver impairment.
Breath tests provide police with a reasonably precise method of getting a BAC measurement.
An EBT (“evidential breath test”) device is just a type of breathalyzer. Generally, breathalyzers are grouped into two types: EBT and PAS (“preliminary alcohol screening”) machines.
PAS devices are typically used by police to determine whether there’s probable cause for a DUI arrest rather than the precise amount of alcohol in a driver’s body. PAS devices are portable, making them easy to use at the roadside. However, some PAS machines aren’t very accurate.
EBT breathalyzers, on the other hand, are for gathering evidence to be used at trial and DMV hearings. EBT machines are typically the most accurate of breath-test devices. Whereas PAS devices are usually small, EBT devices are often large, stationary machines that police keep at the jail or station. And while PAS machines are normally used prior to an arrest, EBT breathalyzers are generally for post-arrest use.
EBT results—provided the machine was properly serviced prior to use—generally are admissible in court to prove a driver’s BAC. But there are a number of DUI defenses related to breathalyzer results.
All states have implied consent laws that require drivers lawfully arrested for driving under the influence to submit to DUI testing. Blood and breath tests are the most commonly used. Some states allow drivers to select the test, while others let officers decide.
Drivers who refuse testing typically face license suspension. The suspension period for a refusal is normally longer than for testing above the legal limit or being convicted of a DUI. A refusal might also lead to having to install an ignition interlock device (IID) and ineligibility for a hardship license. And some states impose criminal penalties such as fines and jail time for refusing a breath test.
Despite the consequences, there may be circumstances where refusing a test is the way to go. Without BAC evidence, it can be more difficult for the prosecution to prove a DUI charge. So, in certain situations, the benefits of refusing may outweigh the drawbacks of taking a test. However, it can be a tough call, and most states don't allow drivers to consult with an attorney prior to deciding whether to submit to DUI testing.