By Attorney Charles E. Liken Jr., former Colorado Deputy District Attorney. Roadside tests you could have refused, machines with maintenance logs, blood vials with chain-of-custody paperwork — the state's evidence is more attackable than it looks from the back of a patrol car.
Charles E. Liken Jr., Esq. — On the Legal Front Lines · Former Government Investigator, Denver Human Services · Licensed Colorado Attorney · 20+ Years in Private Practice · Former Colorado Deputy District Attorney · Colorado Court-Appointed Child and Family Investigator
Every DUI file is a chain: stop → contact → roadsides → arrest → chemical test. A defensible weakness at any link changes the whole case. Finding those weaknesses is literally Attorney Liken's old job.
The officer needs reasonable suspicion for the stop and probable cause for the arrest. Weaving inside your own lane, anonymous tips, and “high-crime area” boilerplate all have case-law limits — and body-cam video often tells a different story than the report.
Where LLF comes in: We pull every video before retention windows lapse and time-stamp the report against it. Government investigators learn quickly: the paper and the footage rarely match perfectly.
In Colorado, roadside sobriety maneuvers (walk-and-turn, one-leg stand, HGN) are voluntary. If you did them, their validity depends on standardized administration, surface, footwear, weather, and your medical realities — all cross-examinable.
Where LLF comes in: Attorney Liken cross-examines SFSTs with the NHTSA manual in hand — scoring deviations and improper instructions convert “failed” into “unreliable”.
Evidentiary breath tests require certified devices, trained operators, and a proper 20-minute observation period. Calibration records, maintenance logs, and operator certifications are all discoverable — and imperfect. The result only creates an inference (§ 42-4-1301(6)(a), C.R.S.), never a verdict.
Where LLF comes in: We subpoena the machine's paper trail as a matter of routine. Files that look airtight on the report page get looser in the maintenance log.
Under express consent (§ 42-4-1301.1(2), C.R.S.) you generally choose blood or breath for alcohol; suspected drug impairment can mean blood, saliva and urine testing. Blood must be drawn, stored, transported, and tested to standard — vials ferment, labels err, and labs have audit histories.
Where LLF comes in: Chain-of-custody attacks are detail warfare. Seven hundred investigations of detail are on your side.
Your BAC at the time of driving is the legal question; the test happens an hour or more later, while absorption may still be raising the number. The gap between driving and testing is a genuine scientific defense, not a trick.
Where LLF comes in: We reconstruct the drinking-and-driving timeline with receipts, witnesses, and toxicology consulting when the numbers justify it.
Ready when you are — talk it through with Attorney Liken.
Start here: a no-charge 20-minute phone call directly with Attorney Liken.
No — roadside maneuvers and the small preliminary breath test are voluntary for adult drivers. The evidentiary blood-or-breath test after arrest is governed separately by the express-consent law, § 42-4-1301.1, C.R.S., with license consequences for refusal.
Yes — certification, calibration, maintenance, operator training, and the required observation period are all attackable, and the result creates only a permissible inference under § 42-4-1301(6)(a), C.R.S.
Alcohol keeps absorbing after you stop drinking, so a test taken an hour after driving can read higher than your level while driving — the legally relevant number. Timeline evidence can make that gap a real defense.
No. Reports are one participant's after-the-fact narrative. Video, dispatch logs, and cross-examination regularly contradict them — which is why preserving video immediately matters.
The state's case arrives as a package: reports, video, machine records, lab records, dispatch logs, training files. Most of it is only produced if someone asks precisely and early. Much of the work happens quietly in the document requests, not the closing argument.
Attorney Liken built these packages for the government and charged cases off them as a former Deputy District Attorney. He knows which page is missing, which log contradicts which timestamp, and which omission means a motion — because omissions were his business.
People tell us daily that they failed the roadsides or blew over the limit, as if the case is over. The number is the beginning of the state's proof problems, not the end of yours.
Before you talk to anyone — DA, DMV, insurance — get twenty minutes with the prosecutor turned defender. Don't let the DMV hearing-request deadline, generally seven days from your notice of revocation, pass.
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