Not necessarily. You should check your school’s policies. Generally, the police may question your son/daughter without your presence. It would be smart to educate your children not to speak with administrators and/or law enforcement if they are brought in for questioning without first having their parents present, who can then better assess whether this is a situation where you need a lawyer.
Yes. Note that the school may have a policy about their security officers searching their lockers. Their backpacks, however, should be off-limits without consent or a warrant. BOTTOM LINE: We want to teach our children and others to respect and cooperate with law enforcement. Most officers are out there to protect and help us. Having said that, it is perfectly fine to know your rights and protect yourselves and your families/friends whenever faced with a situation that could cause trouble in the future.