PBT Results Admissible in DUI Case?

DUI Law and PBT Results

A portable breath test (“PBT”) are used by law enforcement in many situations, including during a DUI investigation.  PBT results are not admissible in a DUI trial.  PBT results are not admissible because they are scientifically unreliable, so it would not be fair for a judge or jury to rely on those test results in determining a person’s guilt or innocence.

There are, however, certain instances when PBT results are admissible as evidence.  In a DUI case, a PBT result may be admissible during a pretrial hearing.  A defense attorney may argue that the police did not have probable cause to believe the suspect was driving under the influence.  During the initial part of an investigation, an officer may ask a driver to take a PBT.  If that PBT result showed a BAC over the legal limit, the law allows the officer to use that result to help him or her decide whether there is probable cause to believe the suspect committed a DUI.  At a pretrial hearing to determine whether the officer had probable cause, the PBT result is admissible.

PBT results are also admissible in minor in possession or underage consumption of alcohol (“MIP”) cases.  In an MIP case, the amount of alcohol in the system is not relevant.  The mere presence of alcohol in the system is enough to have committed the offense.  Apparently, the rationale behind allowing the PBT results in an MIP case and not in a DUI case is that a PBT is reliable enough to detect the presence of alcohol, but not the specific amount of alcohol.

New Case Regarding Inadmissibility of PBT Results in DUI Trial

This distinction was recently addressed by the Colorado Supreme Court in a case called Cain v. People.  In this case, the prosecution introduced PBT results in a DUI trial.  The prosecution argued that, while PBT results are generally inadmissible in DUI trials, the PBT results may be used as impeachment evidence when the defense presents evidence or argument that allows for it.  The Court disagreed and decided that because the DUI statutes specifically prohibit the use of PBT results and because no statute allows for an exception to the general rule that PBT results are inadmissible, using such results as impeachment is also inappropriate.

In this case, the defense attorney asserted that the client had not been drinking, but rather, that the odor of alcohol noted by the officer was because alcohol was spilled.  The client had submitted to a PBT, which had a result of 0.075.  The prosecution argued that defense counsel’s statement that the client had not been drinking opened the door to introduction of the PBT result.  The trial judge disagreed, but did advise that if the client took the stand and actually testified that he was not drinking, then the PBT results would be admisdible.  Because of this, the client decided not to testify.  The defense appealed arguing that PBT results ate not admissible, even as impeachment evidence, and, therefore, the client’s ability to choose whether to testify was improperly infringed upon due to the trial judge’s improper legal decision and advisement.