Not all. In the following six situations, criminal court - and not juvie court - has jurisdiction over defendants who were under 18 at the time of the alleged offense: 1) The defendant was previously convicted of a criminal offense; or 2) The defendant was 16 or 17 and was accused of murder or attempted murder; or 3) The defendant was 16 or 17, he/she was accused of sexual assault or attempted sexual assault involving the use or threatened use of force or violence against the victim, and he/she has a prior delinquency that would be a felony had an adult committed it; or 4) The defendant was 16 or 17, he/she was accused of an an offense or attempted offense involving the use or threatened use of a firearm, and he/she has a prior delinquency that would be a felony had an adult committed it; or 5) The defendant was 16 or 17, he/she was accused of a category A or B felony, but either: the police did not identify the defendant as the suspect until he/she reached 21 years old, or the police did not identity and charge the defendant until he/she reached 20 year old and 3 months; or 6) The defendant was accused of a felony that resulted in death or substantial bodily harm to the victim, the felony was committed on the property of a public or private school when pupils or employees of the school were present or may have been present, at an activity sponsored by a public or private school or on a school bus while the bus was engaged in its official duties, and the the defendant intended to create a great risk of death or substantial bodily harm to more than one person by means of a weapon, device or course of action that would normally be hazardous to the lives of more than one person. Otherwise, all defendants under 18 start out in juvie court. But if the charge is for a serious crime, this could change. As discussed above, the state may try to certify the child as an adult. If the judge agrees, then the child would face charges in criminal court..