how can a person be arrested and charged with possession of a controlled substance if they dont know what the substance is because it was never tested before being charged
Knowledge is a major part of crime. And a defense, knowledge of presence. But, there is a lot more info needed. Don't post here though.
Knowing that what you possess is a controlled substance is an important element in the drug case but it won't stop an arrest. This would be a triable issue. You should have a lawyer. Discuss all of the facts and circumstances with your attorney. S/he would then be able to advise and guide you.
Do you mean the police didn't know what the substance was or the person arrested didn't know?
They can do presumptive tests in the field or if they have probable cause to believe that it is a particular illegal substance, they can make the arrest. For example, if an officer has seen meth hundreds of times in the past and the substance you were caught with looked like meth, was packaged like meth, etc., that may be enough to arrest. The DA will need to prove beyond a reasonable doubt that it was in fact a controlled substance in order to convict, but most often the lab report is not run until after the arrest.
If you're asking whether they can arrest/charge/convict a person of possession when they didn't know what the substance was - the crime is knowingly possessing a controlled substance. The prosecution must prove that the person knew they possessed the substance and that it was a controlled substance. For example, if somebody slipped something in your backpack without your knowledge, you're not "knowingly" possessing that item. If you had a bag of a powder that you truly thought was baking powder, but it was cocaine, you're not knowingly possessing cocaine.
Whether the police/prosecution/judge/jury believe that you didn't know.... that depends on the facts of the case.
Bottom line? Time for a lawyer.
The above answer is for general information only and is based on the information you posted. Every case is fact dependent, so to get a thorough analysis of your situation, you will need to consult face to face with an attorney licensed to practice in the jurisdiction where the incident took place. Do not conclusively rely on any information posted online when deciding what to do about your case.
Two words: probable cause. That's all the police need to make an arrest. So, for example, if they find you in possession of something that looks like drugs, smells like drugs, is packaged like drugs, etc. Then they can legally arrest you. Presumptive chemical tests are not required for an arrest. However, the drugs seized will eventually need to be tested to determine their true content. This testing may not happen until after charging occurs. A negative test will guarantee a dismissal of the charge. Feel free to contact me for consultation. I take cases in Hayward all the time.
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