If you are charged with a crime that is proceeding to trial, the state may wish to call one or more “expert” witnesses to testify at trial. For instance, in a DWI case, the state might use a medical expert, such as a toxicologist, to explain and verify the results of a blood test used to measure blood alcohol content (BAC). Under Texas Rule of Evidence 705(b), the defendant, or the person accused of the crime, has the right to examine or ask questions of the expert witness before the witness testifies about his or her opinion. The defendant can ask the expert any questions about the underlying facts or data that support his or her view.
A 705(b) hearing does not occur in front of a jury. Instead, the judge excuses the jury from the courtroom so that the defense lawyer can conduct the 705(b) examination. The judge excludes the jury from the 705(b) hearing so that there is no danger of the jury hearing inadmissible evidence or hearsay that might come up.
Following a 705(b) hearing, if the judge decides that the underlying facts or data do not form an adequate basis for the expert’s opinion, then the expert’s opinion is not admissible in court. If the data or facts underlying the expert opinion are inadmissible in evidence, then the court must consider whether to limit their use by using a limiting jury instruction or whether they are inadmissible altogether.
Although 705(b) is mandatory, in that if a defendant requests a 705(b) hearing, the judge must grant it, the appellate courts in Texas do not consider it to be a constitutional violation if the judge denies it. In other words, denial of a timely motion for a 705(b) examination typically is not a basis for reversing a criminal conviction, unless it affects a substantial right of the defendant in some manner. If you or a family member is facing any criminal charges, we may be able to help. As experienced Texas criminal defense attorneys, we have the knowledge needed to help you navigate through often-complex criminal proceedings. Call us today at (512) 474-4445 and schedule an appointment with one of our criminal defense lawyers and learn how we can assist you.