Legal Question in Criminal Law in California

It's difficult to figure out what you mean. If you were in a car crash, and you were taken to the hospital, and they did a tox screen, and it came up positive for some drug other than alcohol, and you were charged with a drug DUI based on the results of that test, yes, the test might be offered into evidence by the prosecuting attorney. However, it wouldn't be admitted as evidence automatically, and the good criminal defense attorney you hire will try and keep it out. Also, unlike alcohol for which there are quantitative blood levels such as 0.08 mg/dL, there is no quantity of drugs in your blood that automatically leads to a legal presumption of guilt. We lawyers get to argue over what it all means, and we get to bring in expert toxicologists to attempt to spin the results our way (while telling the truth). If this response doesn't describe your situation, it's your fault for not asking your question in more detail. Please feel free to email me from the Contact Me page at mikestonelaw.com .

Depends. Without knowing all the facts, law and issues involved, no one can tell you. You'll get the answer to that from the criminal case judge as a result of evidence suppression motion[s] you'll have to bring. The same would also apply in a civil case. If you are serious about getting legal help in this, feel free to contact me to discuss. I've been doing these things for over 30 years.

There is no rule against using such evidence against a party. Whether it can be done in your case will depend upon what the case is about, who is alleging what against whom, etc. Without more information, that's the best I can do.