Yes, you can be arrested for selling or buying from an informant, happens every day. The issue then becomes one of credibility which frequently means multiple transactions. Regarding the warrant, credibility is important as well as recency. A defense attorney who is thorough, will sort these issues out for you and get evidence suppressed if the police did not follow the law during the investigation phase. Good Luck !
Yes and yes and yes. You need private counsel for the crimes you are charged with.
R. Jason de Groot, Esq. We do not have an attorney-client relationship. I am not your lawyer. The statements I make do not constitute legal advice. Any statements made by me are based upon the limited facts you have presented, and under the premise that you will consult with a local attorney. This is not an attempt to solicit business. This disclaimer is in addition to any disclaimers that this website has made. I am only licensed in Florida. If you wish to contact the above attorney, see his profile at this website.
A quarter ounce of meth may not seem like a lot, but it's enough for the police and/or a judge to believe that the buyer is a dealer. Less than one gram might be considered "personal use," but 1/4 ounces is about 7 grams, so that amount is going to be thought of as a "dealer amount." Depending on what the warrant is for, when it was obtained, and what other information is available to the judge, the judge could easily issue a warrant for either dealing or simple possession of drugs.
Note that if you"buy" drugs directly from a person (and you hold them in your own hands or whatever), then you are "in possession" of them after you buy them. So you could probably be arrested immediately after buying the drugs. Usually, though, the cops want to prove that you are "selling," so the fact that you buy 7 grams is just one piece of information that the cops will give to the judge when they are asking for a warrant to search your car or home. Usually there would be other information, like statements made by the dealer; the presence of scales; the presence of larger amounts of cash (a few hundred dollars would probably be enough); drugs divided into multiple small packages; cell phone records/text messages that hint at drug dealing.
It can get complicated. Talk to a local criminal defense attorney for details, and ask for an attorney if you are arrested.