When the authorities get a disturbance call, they are duty-bound to not exceed the scope of their authority under federal and California law. They should investigate the requested matter and then leave the premises, unless they have observed a crime being committed in plain view or properly receive reliable information that establishes probable cause to proceed on some other matter. Even with probable cause of a suspected drug crime, the best procedure is to return to the station and swear out a search warrant.
Police in Riverside County were called to a "disturbance" at a home on May 7. It is reported that authorities "found the source of the call" and at the same time "happened upon a man" who was alleged to be in possession of drugs. That obviously cryptic description of events does not allow for an analysis of the facts, but it seems to indicate a possible cause for concern regarding questionable police procedures. It will be up to defense counsel to dissect the facts and determine whether the police had a right to apprehend and search the suspect.
They report that he was found with a pound of marijuana, magic mushrooms, Xanax pills and cannabis wax. The report does not indicate how the police came to discover these drugs or how they were attributed to the suspect. Again, this is part of the basic investigation that defense counsel must make upon taking on the case.
If there was no crime taking place in plain view, the police generally would have had no right to approach and search the suspect, particularly because they were at the premises for something apparently unrelated to a drug crime. California and federal law would require at the least a reasonable suspicion of criminal activity before apprehending and searching the man. If they saw drugs in the general vicinity of the suspect, that mere fact alone would likely not be sufficient to make an arrest.
Source: Palm Desert, CA Patch, "Disturbance Call Leads to Drug Bust in Palm Desert", Alexander Nguyen, May 8, 2015