(a) No person shall be tried for capital crime without presentment or indictment by a grand jury, or for other felony without such presentment or indictment or an information under oath filed by the prosecuting officer of the court, except persons on active duty in the militia when tried by courts martial.

  (b) When authorized by law, a child as therein defined may be charged with a violation of law as an act of delinquency instead of crime and tried without a jury or other requirements applicable to criminal cases. Any child so charged shall, upon demand made as provided by law before a trial in a juvenile proceeding, be tried in an appropriate court as an adult. A child found delinquent shall be disciplined as provided by law.