Breath Testing Instrument
Calibration and Maintenance Records
Colorado requires that breath testing instruments — primarily the Intoxilyzer 9000 — be maintained, calibrated, and certified on a documented schedule. We request the complete inspection and maintenance log for the specific instrument used in your test. We examine whether calibration was current, whether the operator was certified on that instrument, and whether the two required breath samples were within the statutory tolerance of each other.
- Instrument's certificate of analysis and most recent inspection records
- Operator's current certification on the specific instrument model
- Whether required 20-minute observation period was maintained
- Whether the two breath samples are within 0.020 g/210L of each other
- CDPHE records for the specific instrument serial number
What we examine does not predict an outcome. Each case depends on its own record and the applicable law.
Blood Analysis
Blood Draw Chain of Custody
A blood draw result is only as reliable as its collection, storage, and laboratory analysis procedures. We obtain the complete chain of custody documentation: the kit lot number and expiration date, the nurse or phlebotomist's qualifications, the evidence seal documentation, and the laboratory's analytical records including the internal standard and the analyst's qualifications.
- Blood draw kit lot number and expiration date
- Phlebotomist or nurse qualifications and certification
- Time between draw and refrigeration (fermentation potential)
- Unbroken evidence seal from draw through laboratory receipt
- Lab analyst's qualifications and headspace gas chromatography methodology
Chain of custody defects are factual questions. Whether they affect the result in a given case depends on the specific record.
Standardized Field Sobriety Tests
NHTSA Protocol Administration
The three standardized field sobriety tests — the Horizontal Gaze Nystagmus test, the Walk-and-Turn test, and the One-Leg-Stand test — are validated only when administered strictly according to NHTSA protocol. Our attorneys hold NHTSA SFST Practitioner certification — the same credential law enforcement uses — and can evaluate every element of how the tests were given against the published standard.
- HGN: whether equal pursuit, distinct and sustained nystagmus, and onset before 45 degrees were properly assessed
- WAT: whether a proper instructional stage and walking surface were provided
- OLS: whether the 30-second count and balance requirements match the record
- Officer's NHTSA SFST training records and most recent recertification date
- Non-standardized tests that may have been administered in addition to the validated three
Protocol deviation alone does not automatically produce a legal defense. The significance depends on the nature of the deviation and how the officer scored and testified.
Fourth Amendment
The Reason for the Initial Stop
A traffic stop requires reasonable articulable suspicion that a traffic infraction or criminal activity occurred. We examine the officer's stated basis for the stop against the body-worn camera footage and the dispatch log. If the stop was not supported by the required legal standard, evidence obtained during and after the stop may be subject to suppression under the Fourth Amendment.
- Officer's articulation of reasonable suspicion in the arrest affidavit
- Whether the body-worn camera footage supports or contradicts that articulation
- Duration of the stop and when it converted from a traffic stop to a DUI investigation
- Whether a checkpoint was lawfully established and conducted
Suppression of evidence requires a legal standard to be met. Not every questionable stop produces a successful suppression motion.
Video Evidence
Body-Worn Camera Footage
Body-worn camera footage is frequently the most probative evidence in a DUI case — and it cuts both ways. We obtain all available footage: the officer's body camera, any dashboard camera from the patrol vehicle, and booking facility video. The footage is compared against the arrest report and the officer's testimony. Discrepancies between the officer's written account and the video record are relevant to both the criminal and DMV proceedings.
- Complete body-worn camera footage from initial stop through booking
- Dashboard camera footage if a patrol vehicle was used
- Whether the camera was properly activated and maintained recording
- Comparison of the officer's report against what the footage shows
Video evidence must be preserved through a timely preservation demand. Its availability and completeness vary by agency and by how quickly the request is made.
Pharmacokinetics
Rising Blood Alcohol
Blood alcohol level rises as alcohol is absorbed after drinking, then falls during elimination. If a person consumed alcohol shortly before driving and was tested an hour or more after the stop, the test result may be higher than the BAC at the time of driving. This pharmacokinetic principle — retrograde extrapolation — is examined in cases where the facts support a meaningful timing gap between driving and testing.
- Time of last drink versus time of stop versus time of test
- Type and quantity of alcohol consumed and over what period
- Whether food was consumed before or during drinking
- Whether a forensic toxicologist's opinion is warranted by the record
Rising alcohol analysis is a scientific question requiring careful factual development. It is not a defense that applies in every case.
Medical Conditions
Conditions That Can Appear as Impairment
Certain medical conditions produce signs that officers are trained to associate with alcohol impairment: nystagmus from inner ear disorders, balance issues from neurological conditions, slurred speech from medications, and elevated mouth alcohol from acid reflux or a high-protein diet that can produce falsely elevated breath readings. We review the client's medical history for any condition that may have contributed to the officer's observations or the test result.
- Conditions causing nystagmus independent of alcohol: inner ear disorders, certain medications, seizure disorders
- Diabetic ketoacidosis as a source of mouth alcohol misread as ethanol
- GERD and acid reflux as a source of elevated breath test readings
- Medications that affect balance, speech, or the appearance of coordination
Medical conditions are relevant to the evidence record. Whether they support a defense depends on the specific facts and the strength of the medical documentation.
