Yes, the police can question a minor without their parent(s) present if that minor is not in custody.  This often happens when an officer has a reasonable belief that a minor has violated the law. They can detain the minor to conduct an investigation. During this initial detention, the police are not required to let a minor call their parents.   However, if the minor is in custody (i.e. arrest), that changes things. In such a case, they have the right to call their parents and have their parents present during questioning.  Basically, anytime that the minor's Miranda rights are implicated they have a right to speak with their parents and have them present.Note:  Regardless of age, if someone is in custody and not given the Miranda warning no statements made by them can be used later against them.  However, prior to being placed in custody any statements made can be used; or if they were read their rights and made voluntary statements after, those statements may be used.