Under the facts as presented, there would appear to be no violation of your Fourth Amendment rights. The police were investigating what they believed may have been a crime in progress based upon the telephone call. It was your friend's back yard that they went into, so they did not need a warrant, Even if they did, it would have been your friend's who would have charged the warrant-less search. As to taking you in for being under the infulence- they had the probable cause based upon the physical symptome observed, consequently, your rights were not violated.
Why would it be a crime to be sitting on private property under the influence? They would still need probable cause to place you under arrest and I would think you could challenge the arrest. You need to hire a local criminal attorney.
Answers presented on this website are intended only for informational purposes and any use of the contained material is at the users own risk. Answers are intended exclusively as a public resource for general information, and this information is intended, but is not promised or guaranteed to be, correct, up-to-date, or complete. This material is not intended to constitute legal advice, as an agreement to create an attorney-client relationship with the law offices of Mitchell S. Sexner & Associates LLC, or the provision of legal services, and receipt of this information does not constitute such an agreement. If legal or other specific expert advice is required, then the services of a competent professional should be sought.O