Drunk Driving Defense Lawyer

Challenge the accuracy of Preliminary Breath Test (PBT)

Michael J. Zarrella, Esq

Law Office Address:

127 Dorrance Street

Providence Rhode island 02903

Cell: 401-523-5271

Office 401-490-6820

Fax: 401-490-3207


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Fighting the Preliminary Breath Test (PBT)


Preliminary Breath Test (PBT) in Rhode Island

Many cities and town are currently using PBT in determining if a person should be arrested in a drunk driving case. A Preliminary Breath Test (PBT) is given to drivers, often as part of the field sobriety tests.  Under Rhode Island law, the PBT test and results are not admissible at trial, but can only be used as probable cause for an arrest.  Refusal to take a Preliminary Breath Test (PBT) in Rhode island is only a fine, there is no loss of license.  

The PBT is a hand-held portable breath test device,  it is not the same as the breathalyzer machine at the police station.  If a police officer has reason to believe that an operator of a motor vehicle is under the influence, he or she may require that person to submit to a preliminary breath test (PBT).  The sole purpose of the PBT is to help determine whether or not the police has a sufficient probable cause.

There are many problem with the PBT. First and foremost, the PBT often does not distinguish between alcohol that is in a operator’s mouth and the alcohol that is in their blood. Therefore, often times, the test can give a higher result than the actual blood alcohol content.  This is problematic in two ways. First, it can give a police officer misinformation in determining if someone is under the influence. Secondly,  it can cause a driver to later refuse a test back at the station, because he lacked the knowledge that his PBT may have been wrong. Therefore, he may believe his PBT was accurate, when in fact his BAC (Blood Alcohol Content) may have been much lower.


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Should you take the Preliminary Breath Test (PBT) in Rhode Island?

There are many compelling points defending both cases, and through being informed, you can make a decision that is right for you.  If you were to take the test and pass, the officer would be less inclined to arrest you.  However, if you take the test and fail you give the state more probable cause. Furthermore, although the PBT cannot be used against you at trial, the prosecution and likely the judge will know the results, making it more complicated for you.

Under Rhode Island law, there is a requirement that the subject be continuously observed for a period of fifteen or more minutes before blowing into the breathalyzer machine at the station. This is done in order to assure that there is no foreign material or alcohol in the subject’s mouth that can throw of the results.  In addition, the breath test at the station has what is called a slope detector to prevent alcohol in the mouth from being read, which can affect the test negatively for the operator.  Most of the preliminary machine often do not this.  Therefore, PBT test can be off.

Again, measurements from a PBT are inadmissible in court, for a reason. They lack the precondition exactness needed for evidence because they often do not have the necessary updated calibration and proper certifications necessary. In short, they are not as reliable as the machines at the station.


The Preliminary Breath Test (PBT) Statute

§ 31-27-2.3  Revocation of license upon refusal to submit to preliminary breath test. – (a) When a law enforcement officer has reason to believe that a person is driving or in actual physical control of any motor vehicle in this state while under the influence of alcohol, the law enforcement officer may require the person to submit to a preliminary breath analysis for the purpose of determining the person's blood alcohol content. The breath analysis must be administered immediately upon the law enforcement officer's formulation of a reasonable belief that the person is driving or in actual control of a motor vehicle while under the influence of alcohol, or immediately upon the stop of the person, whichever is later in time. Any chemical breath analysis required under this section must be administered with a device and in a manner approved by the director of the department of health for that purpose. The result of a preliminary chemical breath analysis may be used for the purpose of guiding the officer in deciding whether an arrest should be made. When a driver is arrested following a preliminary breath analysis, tests may be taken pursuant to § 31-27-2.1. The results of a preliminary breath test may not be used as evidence in any administrative or court proceeding involving driving while intoxicated or refusing to take a breathalyzer test, except as evidence of probable cause in making the initial arrest.

  (b) If a person refuses, upon a lawful request of a law enforcement officer, to submit to a test under subsection (a) of this section, that person shall be guilty of an infraction and shall be subject to the penalty provided in § 31-41.1-4. However, it shall be a defense to a charge of refusing a validly requested preliminary breath analysis that the medical condition of a person precluded the giving of any such test.