All law enforcement personnel or other governmental officials having custody of any person under eighteen years of age shall inform the person in custody, using developmentally appropriate language and without unnecessary delay, of such person’s right to call or consult an attorney who is retained by or appointed on behalf of such person or whom the person may desire to consult and, except when exigent circumstances exist, shall permit such person to call or consult such attorney without delay. An attorney shall be permitted to see and consult with the person in custody alone and in private at the place of custody.