Criminal Defense Lawyer | DWI, Drug, Theft & Assault Charges

The Textbook Example

Toxicologist or Pharmacist vs. Police Officer:

Rules allow for both to testify about intoxication in a DWI trial in most situations as expert witnesses.  It is not uncommon for some police to have drug recognition training, but the lines can be quickly blurred in a courtroom if the officer and prosecutor over-step their bounds.

A police officer might try to make medical conclusions based on factors observed.  The conclusions might include the individual has ingested CNS depressants or the individual is on opioids, or is intoxicated due to a combination of substances ingested.  They base this on training provided to them either at the police academy or at advanced courses and experience from work.

So a police officer under-qualified expert often describes something which may or may not be obvious to everyone and tries to explain why.  That’s all fine but when pressed on details, alternate causes, or any medical principles at all — an officer normally retreats into, “I can’t answer that because I’m not a doctor.”  See how unfair that is?  They are fine opining about how guilty the defendant is but basically can’t be cross-examined at all because of their lack of knowledge.  It is a lose-lose for the defense.

The toxicologist or the pharmacist, on the other hand, has had far more academic training — in addition to applied training — and can discuss specific evidence which must be present to make certain conclusions.  With most drugs, they need to know someone’s medical history and history of taking prescription pills to know how much a certain drug would affect them.  They are also aware of medical journals, studies, and research which often goes contrary to conventional wisdom but is clinically tested medical fact.

The toxicologist and/or the pharmacist will concede points to both prosecution and defense lawyers so long as they are consistent with accepted conclusions in the scientific community.

To analogize — it would be like me saying that I’ve seen clouds my whole life so I’m an expert on the weather.  I throw out a few cloud types I might have picked up on the way… the direction of the wind maybe and come to the conclusion it will rain when it’s mostly cloudy.  When I’m pressed on details about barometric pressure, dew-point, and ionization of the clouds I shut down and say — “well, I’m not a meteorologist!  I just know it’s going to rain!”

Rule 701:  

“If a witness is not testifying as an expert, testimony in the form of an opinion is limited to one that is:

1. (a)  rationally based on the witness’s perception; and
2. (b)  helpful to clearly understanding the witness’s testimony or to determining a fact in issue.”

Rule 702. Testimony by Expert Witnesses:

“A witness who is qualified as an expert by knowledge, skill, experience, training, or education may testify in the form of an opinion or otherwise if the expert’s scientific, technical, or other specialized knowledge will help the trier of fact to understand the evidence or to determine a fact in issue.”

So — in theory at least — an expert has scientific, technical or other specialized knowledge which everyone else doesn’t have.  They normally attain the knowledge from formal education, academic journals, and real world experience.  So having blood in my veins for my entire life doesn’t make me a blood expert… being an accredited scientist who keeps up with medical journals probably does.  See the difference?

The Court’s Gatekeeping Function

The Courts have what is known in caselaw as a “gatekeeping” function.  This is to say the Judge must make the determination whether an individual is acceptable as an expert or not.  Several important cases expand the rules.  See Daubert v. Merrell Dow Pharms, 509 U.S 579 (1993) and Kelly v. State, 824 S.W.2d 568 (Tex. 1992).

The Judge is bound, however, by appellate precedent and to a lesser extent by “the way we do things around here” as I discussed earlier.  Case law makes clear, for instance, that a police officer who is fully accredited can testify as in expert in intoxication due to alcohol.  Officers with specific training about the effects of drugs on the body can almost always testify as drug recognition experts.

“The way we do things around here” sometimes kicks in when defense lawyers don’t make routine challenges so that when one finally does — the Judge might not take the challenge seriously because the Courts have always allowed a certain person to testify as an expert.  Certainly everyone else can’t be wrong?

So How Do We Deal with “Instant Experts” When Defending People?

We fight through it.  We make the proper challenges and the proper objections at the appropriate times.  If we must cross examine an instant expert then we do it wisely by logically cornering and limiting what they can credibly say.  We expose the massive gaps in their knowledge.  If it is appropriate in a given case — we present our own expert with the proper credentials.