Thanks for your question. It certainly does appear that you were set up. I'm assuming you were expecting the "prostitute" and that, obviously, you wanted to let her in. From there, the police are claiming that they entered to safeguard the officer and, of course, the weed was in plain view.
According to According to the US Supreme Court
, police are legally allowed to lie everywhere except when under oath on the stand, and sting operations are lawful. From there though, with regard to search and seizure the police need a warrant to search your premises or an exception to the warrant requirement.
While you clearly have issues here if there could have been no way for them to have seen what was in your tupperware bowl, police improprieties don't in and of themselves mean your case can't and won't get prosecuted. There are no hard and fast rules when it comes to 4th Amendment issues. The Supreme Court has said that what is Constutitional must get determined on a case by case basis at special suppression hearings designed to challenge the police conduct.
The standard that a court is to apply is "what a reasonable police officer would do under all the circumstances." So at a hearing, the prosecutor would put the police officer on the stand, and try to bring out facts that would make it appear to the judge that everything the police did under the circumstances was reasonable. When the State is finished your lawyer would cross examine to try to point out where and how the police overstepped their authority in violation of your constitutional rights.
You can bet that the police will try to say that they came into your house to protect their officer. Emergency situations are a legitimate exception to the warrant requirement. From there they will likely try to show that the search was "incident to the arrest" which does give them a right to search what's in plain view and areas that were in your immediate vicinity and that you consented to anything further.
How will this come out? I couldn't say. However, suppression hearings, no matter how damaging the fact pattern, are never a slam-dunk for the defense. Courts are inclined not to second-guess the procedures of police out in the field. They know their job is a difficult one and courts don't want to hamstring the police in their efforts to thwart crime. So in most cases, the courts will find the police actions reasonable under the circumstances, and the evidence against you would come in at trial
You will need a lawyer to fight this case, and he'll be able to see and hear evidence that I cannot, before he advises you. He should be able to tell you once he's done some work on the case how viable your suppression hearing would be and, if you lose the hearing and the evidence comes in against you, what defenses you might have at trial. Then you will be able to decide whether to go for the hearing (usually held at the end of the case right before jury selection) or to cut your losses early and give up your right to a hearing in trade for a very favorable disposition on the case.
Edited by FranL on 2/2/2011 at 6:09 AM EST