Legal Question in Criminal Law in California

Re: drug test

If you are talking about a driving under the influence situation, yes, you can be charged with a DUI if you refuse to take a blood or urine test if the cops have suspicion you have been driving under influence of drugs. Refusal has even more serious consequences in that you are risking losing your driver license for 1 year upon first conviction or first suspension by the DMV.

Re: drug test

Yes, if the evidence supports such a conviction. The prosecutor may be able to prove you were under the influence by other means, such your behavior at the time and evidence that you used a drug beforehand.