Admissible DUI Evidence

In a criminal case in the state of Arizona, evidence is important to both the prosecution and to the defense as it is the only information that may be used by a judge or a jury when considering the merits of a charge or charges faced by a defendant in a criminal matter. When evidence of driving under the influence (DUI) is entered before the judge or jury either by documents or testimony, it is important that it is relevant, reliable and not prejudiced. If the evidence meets all of these requirements, it is referred to as admissible evidence.

In the state of Arizona, preliminary breath testing results from a portable instrument used by law enforcement officers in the filed is not evidence that is admissible in a DUI case. Evidence that is admissible is evidentiary breath testing results and analysis of blood that is obtained, usually, through the execution of a search warrant. In order to make certain that evidence in support of the DUI charges you face is relevant, reliable and not prejudiced it is important that you should consult experienced Arizona DUI lawyers like those associated with the Law Offices of Craig W. Penrod, P.C.

Evidence is considered to be relevant if proves or disproves a point that is being made by either the prosecution or the defense. However, if the evidence causes the judge or the jury to look unfavorably at either the prosecution or the defense due to reasons unrelated to the issues involved in the case, the judge may find that it is not admissible as evidence for consideration.

Evidence is considered to be reliable if the party entering the evidence is able to prove that the source of the evidence is itself reliable. For example, if witness testimony is presented as evidence, the side that introduces the evidence are required to show that the witness is credible and has knowledge about the subject matter that he or she is testifying about.

Hearsay information is considered unreliable and thus inadmissible in court because hearsay is information that is gathered second hand. The trial judge is required to exclude unreliable testimonies from the case.

The United States Supreme Court first laid out the reliability requirements for expert witnesses in Daubert v. Merrell Dow Pharmaceuticals, Inc. The court decided on four factors that trial courts may look at when evaluating the reliability of an expert witness. The factors outlined by the high court are:

  • whether the evidence has been subject to scientific testing and, if so, what methodology was used;
  • whether the evidence has been reviewed by peers or a scientific publication;
  • what is the known potential rate of error; and
  • is the evidence generally accepted in the scientific community.If documents are entered as evidence, proof is required as to the authenticity of the evidence.

Also, a clear chain of custody is required showing the original creator of the document to the person who now holds it. There are other factors that may render evidence inadmissible in court. For example, if the law enforcement officer investigating the case seized evidence without a search warrant or probable cause, it may not be used in court.

It is important that your DUI legal situation should be handled by expert professionals with the experience possessed by the attorneys at the Law Offices of Craig W. Penrod, P.C.