When you get pulled over for DUI in Maryland, the police officer will likely ask you to step out of the car and perform a series of field sobriety tests. He or she may also ask you to breathe into a little machine. Then, if you are taken to the police station, you may be asked to breathe into a completely different machine. This is because in Maryland, drivers suspected of being under the influence can be subjected to two different breath tests.

Preliminary breath test (PBT) in the field

The first breath test is usually administered at the site of the DUI stop, on the side of the road, prior to a potential DUI arrest. This is referred to as the preliminary breath test (PBT). Many police officers enforcing traffic laws have a portable breath test device in their vehicles, which is used to estimate the quantity of alcohol in a person’s breath. You will be asked to blow into the device after you have completed the field sobriety tests.

If a police officer asks you to take a preliminary breath test, it is important to understand that complying with that request is not mandatory. Refusing to take the breath test on-site cannot affect whether or not you keep your driver’s license. If you refuse to take the test, your refusal may not be used by the prosecution in any court action against you.

Unreliability of the preliminary breath test

PBT’s have a poor record of accuracy. These devices are generally not calibrated properly, nor as often as official breathalyzer machines located in police stations. Because portable breathalyzers are not maintained under controlled conditions, the possibility of greater errors in the results exists. The change in temperature in the car, as well as the constant movement of the vehicles, can render the devices inaccurate.

Breath test at the police station

The second breath test is given at a police station. This is an official test administered by a police officer with special certification to do so. The results from this machine are generally assumed to be much more accurate than those obtained from the PBT. Under the law, the results of this official test can be used against you in a court of law.

If you refuse to take a breath test back at the station, you can have your driver’s license suspended or revoked by the Motor Vehicle Administration (MVA). The officer will take your driver’s license and give you a temporary license. He or she will hand you paperwork that notifies you of your right to an MVA hearing where you may argue against having your driving privileges affected.

Of course, if you submit to the police station breath test, you are giving the prosecutor additional evidence to use against you. No matter what you decide, your DUI defense lawyer can help you fight the charges against you.

At Carey Law Office, DUI attorney Joseph Carey understands the various errors that can accompany both the portable breath test and police station breath test during a DUI investigation. We know how to fight to have your DUI charges dropped, and to achieve the best possible outcome in your case. To set up a consultation with a DUI attorney in Bowie or Crofton, MD, give us a call today at 301.464.2500 or leave us a message through our contact form.