In Utah, a child who is under 14 years of age is presumed not adequately mature and experienced to knowingly and voluntarily waive or understand their rights unless a parent, guardian, or legal custodian is present.
If the child is 14 years of age or older, the minor is presumed capable of knowingly and voluntarily waiving the minor's rights without the benefit of having a parent, guardian, or legal custodian present during questioning.
That said, it appears, that the backpack is the issue here. Your son had an expectation of privacy in the contents of that bag. Depending on the facts, the evidence found in the back pack may be able to be suppressed.
It appears that your son experienced a level 2 detention. A level 2 detention must be based on some type of reasonable suspicion. It is hard to say what the reasonable suspicion for detaining your son was, from the facts, as you have presented them. Moreover, if your son was detained illegally, all the evidence against him could be suppressed.
Hope this helps.
Outrageous that they are charging resisting arrest and failure to respond to a command. From what you have explained, your son resisted an illegal seizure of his telephone.....at a time when he was not under arrest. It appears that police THEN decided to handcuff your son, given that he had the audacity to refuse consent to search his phone or backpack. What command did he refuse to respond to? "Give me your phone?" Police cannot simply command a person to do anything that police want them to,, when will police learn this? Re: possession of marijuana, if the cops had reason to arrest your son BEFORE they searched the backpack, then it would be a lawful "search incident to arrest." Given that they arrested him for what was INSIDE the backpack, and for his alleged obstructionist behavior in refusing to voluntarily allow police to see what was inside the backpack, they cant rely on search incident to arrest. If cops had a legitimate reason to stop him, all he has to give them is his name and possibly dob.
A direct answer to your question is NO. Nobody EVER has to answer police questions besides "what's your name and dob?" No person, juvenile or adult, can be forced to say anything, and even if a juvenile does NOT ask for his or her parents, the cops cant make him say a thing.
The answer above should not be considered to be legal advice; however, please feel free to contact me if you are seeking to hire an experienced criminal defense attorney to help you sort this matter out. TheLawOfficesofJenniferAFitzgerald.weebly.com