2. The trial court did not err in concluding that a juvenile who was 17 1/2 years of age, had completed the 11th grade, had been adjudicated delinquent of 10 felony-type offenses, had presented no evidence that he had suffered any physical deprivation during interrogation, had been arrested following a high-speed chase, had received Miranda warnings before each admitted statement, had been informed by his interrogators that they were working for the sheriffs office, and who had been found to have the sufficient maturity and intelligence to understand his rights, did in fact knowingly, intelligently and voluntarily waive his right to remain silent despite the fact that he was not given the opportunity to speak with a parent or other responsible adult.