It amazes me that so many little legends and half-truths survive and propagate when it comes to the law.
There are three levels of encounters between citizens and law enforcement: consensual, <i>Terry</i>, and arrest.
A consensual encounter needs absolutely no justification. An officer is free to approach anyone and ask them questions for any reason, as long as the person is free to disregard the questions and go about his business.
A <i>Terry</i> stop must be predicated on “reasonable suspicion.” This is less stringent than probable cause, but is something more than an inchoate, unspecified hunch. A Terry stop involves a brief detention, and may include a pat-down search of outer garments for the officer’s protection.
An arrest must be predicated on probable cause.
As to the facts you relate:
The officer was perfectly entitled to initiate a traffic stop for the failed tailight. This is true even if it’s a pretext for some other reason. As long as the stop is objectively reasonable, the courts will not inquire further.
Once stopped, the officer cannot escalate the encounter beyond its inital bounds, unless there is a further reasonable, articulable suspicion to do so.
It is of no moment that the car was borrowed, by the way; the law forbids anyone from operating a vehicle without tailights. You might get a dismissal from a judge, but it certainly provides probable cause for the stop.
Once stopped, the officer detected an odor of alcohol. The officer can certainly say that each of you looked under 21 - since you all were, he’s safe in saying that. This provided his reasonable, articulable suspicion to investigate further. Assuming there is a Pennsylvania law that allows breathalyzer tests as evidence of possession of alcohol by minors, the results gave him probable cause to arrest you.
So, to answer your questions: “we were only breathalyzed because he had been pulled over. as soon as his thang was over with, we shoulda been free to go. does being a passenger in a car somehow waive some rights?”
Yes, it does, but that doesn’t come into play here. You were breathalyzed because you looked under 21, which, combined with the odor of alcohol, gave the officer reasonable and articulable suspicion that you were minors in possession of alcohol.
“and he breathalyzed us without proof that we were under 21, and then used a .10 result as justification for searching us. can he search without consent in that situation? he also searched the car w/o consent.”
He doesn’t need proof - just reasonable, articulable suspicion. Once you blew 0.10, he had probable cause to arrest you. At that point, he is permitted, without your consent, to search you incident to arrest, as well as to search the area within your immediate reach and control.
I’m sorry you feel “…jerked around by the fucking suburban law system because of this,” but since your conduct was, in fact, illegal, I guess I’m a little curious why you’re indignant. The purpose of the “fucking suburban law system,” after all, is to enforce the fucking suburban laws. If you do not wish to be jerked around thereby, one good approach is to not break the fucking law.