As I see it, here in the US we have the Fourth Amendment to the Constitution which guarantees the right to privacy in your person and your private property. 'Reasonable cause' has to do with a crime/offense that has already been committed and the police believe the person they are contacting has committed that crime/offense. One can usually expect an arrest or 'cite and release' when confronted by the police where reasonable cause exists. However, 'Reasonable Suspicion' has to do with some articulable fact that a crime/offense may have been or is about to be committed.
When you are approached by the police and they clearly want to talk with you the first words uttered from you should be, "Has a crime or offense been committed"? If the police respond with something like, "I'm not sure" or "Maybe" or something to that affect, they are operating under reasonable suspicion and fishing for information. Yes, the police are able to approach you anywhere in a public place or go to your home or other private property for a 'knock and talk' discussion but in no case are you obliged to answer any questions or even talk with them (Fifth Amendment to the Constitution). If the police tell you that they believe a crime/offence has been committed, and you may be involved somehow, do not under any circumstances talk with them about the crime/offense because ANY ‘voluntary statements’ made by you can and will be used against you. If the offense is a crime and you are taken into custody, the police are required to advise you of your Miranda Rights which are:
1. You have the right to remain silent.
2. You have the right to have an attorney present before you answer any questions
3. If you can’t afford an attorney one will be appointed by the court for you
4. Anything you say can and will be used against you in a Court of Law
There are exceptions to every rule. The police in most all locals have the right to stop and talk to you but they cannot unreasonably detain you unless you are under arrest. Arrest means that you are taken into physical custody, held long enough to issue a citation or the police restrict you from just walking away.
Another BIG EXCEPTION if you are operating a motor vehicle you must produce a driver license or you can be detained long enough to assure your correct identity and validity of your license. Sometimes that’s a chauffeured trip to the police station and a walk back to your car or impound lot and a hefty tow bill.
As for pictures, anyone can take a (not lewd) photo of anyone else in a public place unless it posted as forbidden or there is some expectation of privacy. Public nude beaches, for example, often are posted for everyone but the police.
As for searching; the police may give a quick ‘pat down’ for weapons and their protection. Cops are taught how to do this at the academy so they don’t get fondling charges brought against them. Vehicle and private space searches can only be done with your consent or a warrant.
I have mixed feelings about allowing a search of my vehicle or private space (property). If I were in Ellie’s shoes, if the female cop has a good attitude, OK maybe. Assh*le cops get a warrant period since they MUST have enough probable cause to convince a judge or magistrate that they need to search your private property for evidence of a crime. Some cops will threaten you that they will get a warrant if you don't let them do a consentual search. It's usually an unfounded threat and a whole different legal situation if they do. It's inconvenient for both you and the cop but what the hell make ‘em do their job right.
By the way, the photo the cops took, count on it being passed around the ‘cop shop’ if for nothing more than a laugh. It’ll probably get posted on the bulletin board for a while. And count on a record of some sort being made about the encounter even if it’s just a simple dispatch log entry.
OK, sorry for the rant. I am not a cop nor am I anti-police. I just dislike watching my civil rights get slowly erroded away.