Experts for DUI Chemical Testing

Experts can be used in DUI cases involving chemical testing. Both the state and defense might use experts in Toxicology, Pharmacology, Pharmacokinetics, Psychiatry and the Practice of Medicine.

Experts in different categories have different educational, experience and training requirements. Criminal defense attorneys might use these types of experts in the most serious types of DUI charges including DUI manslaughter and DUI with serious bodily injury.


A toxicologist with the Florida Department of Law Enforcement (FDLE) analyzes samples of blood and urine for the presence, or absence, of alcohol and other drugs of abuse. For example, a person who is arrested for “driving under the influence” may be required to give a blood sample for analysis.

A series of test procedures is then completed on the sample to determine the type of any intoxicating chemicals present. Toxicologists conduct presumptive and confirmatory testing.

The qualifications for employment as a Toxicologist with FDLE are having a bachelor or advanced degree in physical, biological, or forensic science from an accredited college. A FDLE Toxicologist is not required to have an advanced degree in Pharmacology or a medical degree.

A Toxicologist may not offer an opinion on a matter outside the scope of the education and employment as a Toxicologist, i.e. any testimony other than what tests the Toxicologist ran, how the tests work, and what substances were located in the subject urine or blood, based upon FLDE’s own description of the employment scope of their toxicologists in the above section of this motion.

Within the scope of Pharmacology, Psychiatry, and Medical Doctors under Florida Statutes §§ 458.305(3), 465.003(13) and 490.003(4) Fla. Stat. (2016), expert testimony might include:

  • psychological diagnosis;
  • what medications are prescribed to assist in the alleviation of symptoms of any diagnosis;
  • the effects of any medications;
  • the route a substance takes in the body;
  • the substance’s absorption, distribution, metabolism, and excretion.

In order for a Toxicologist to testify to these subjects, the expert would be required to be licensed in Florida as a Medical Doctor, Pharmacist, and/or Psychiatrist.

Normally, a toxicologist is not educated, trained or experienced on mental, psychological or psychiatric matters. The expert is not generally permitted to opine about whether a person, at any given time, was:

  • suffering from a mental disease or defect, or
  • under the influence of any substance to the extent that his normal faculties were impaired, or
  • under the influence of mental or emotional disturbance, or whether observed or described symptoms indicate that a person “does not have full cognitive capabilities.”

See State v. Covington, 08CF009312A (Order, Judge Fuente, May 11, 2015).


Florida Statute Section 490.003(4) defines the practice of psychology as:

[T]he observations, description, evaluation, interpretation, and modification of human behavior, by the use of scientific and applied psychological principles, methods, and procedures, for the purpose of describing, preventing, alleviating, or eliminating symptomatic, maladaptive, or undesired behavior and of enhancing interpersonal behavioral health and mental or psychological health.


Florida Statute Section 465.003(13) defines the “[p]ractice of the profession of pharmacy as:

“Includ[ing] compounding, dispensing, and consulting concerning contents, therapeutic values, and uses of any medicinal drug; consulting concerning therapeutic values and interactions of patent or proprietary preparations, whether pursuant to prescriptions or in the absence and entirely independent of such prescriptions or orders; and other pharmaceutical services.”

For purposes of this subsection, “other pharmaceutical services” means the monitoring of the patient’s drug therapy and assisting the patient in the management of his or her drug therapy, and includes review of the patient’s drug therapy and communication with the patient’s prescribing health care provider as licensed under chapter 458, chapter 459, chapter  461, or chapter 466, or similar statutory provision in another jurisdiction, or such provider’s agent or such other persons as specifically authorized by the patient, regarding the drug therapy.

However, nothing in this subsection may be interpreted to permit an alteration of a prescriber’s directions, the diagnosis or treatment of any disease, the initiation of any drug therapy, the practice of medicine, or the practice of osteopathic medicine, unless otherwise permitted by law.

The Practice of Medicine

Florida Statute Section 458.305(3) defines the “practice of medicine” as:

“[T]he diagnosis, treatment, operation, or prescription for any human disease, pain, injury, deformity, or other physical or mental condition.”

This article was last updated on Monday, August 21, 2023.