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Driving Under The Influence Of Drugs

Thanks to the reliable breathalyzer, the typical DUI is often an open and shut case. Implied consent laws mean that all drivers have consented to a BAC test and the results provide key evidence. Sure, there are ways to challenge the evidence, but usually on a technicality (i.e. the machine is overdue for a routine maintenance and accuracy check).

But drugs other than alcohol? Not as simple to prove, but Illinois police have their methods.

So in the absence of a magical machine that tells officers how much of which drug influenced the driver at the time he or she was driving, how do they gather evidence proving the DUI beyond a reasonable doubt?

Alcohol metabolizes quickly, within about an hour of consumption per drink, but different drugs stay in the body for varying amounts of time. If someone who is just a poor driver but suspected of a DUI fails a drug test, how do police know he or she was under the influence of that drug while driving?

Prosecution uses a combination of circumstantial evidence (swerving, extreme paranoia), physical signs of the driver (track marks, dialated pupils), results of a drug test and the testimony of a drug recognition expert, according to Peoria, Illinois DUI attorneys at Miller & Pugh Law Offices, P.C. (FindLaw listing).

Drug recognition experts usually follow this 12-step process to evaluate suspected drug impairment (Wikipedia):

  1. Breathalyzer test
  2. Interview of arresting officer
  3. Preliminary examination
  4. Eye examination
  5. Divided attention tests
  6. Examination of vital signs
  7. Dark room examinations
  8. Examination of muscle tone
  9. Examination of injection sites
  10. Suspect's statements, other observations
  11. Opinion of the evaluator
  12. Toxicological examination 

It's quite an extensive method, as you can see, and way more involved than a simple breathalyzer. Drug-related DUIs are treated just like alcohol-related DUIs in court.