Final answer:
The dual court system refers to instances when a juvenile is under the jurisdiction of both the juvenile and criminal courts, especially when a juvenile is charged with a serious offense that warrants consideration beyond juvenile rehabilitation efforts.
Step-by-step explanation:
The situation in which a juvenile is under the jurisdiction of both the juvenile and criminal courts is referred to as a dual court system. This occurs when a juvenile is charged with a serious crime that may be tried in both the juvenile system for its tailored rehabilitative approach and in the criminal court due to the seriousness of the offense. This often happens when the crimes committed are so serious that they are considered beyond the scope of juvenile punishment or rehabilitation efforts. In such scenarios, the juvenile may be tried as an adult, reflecting the opinion held by some that trying youths as adults is necessary when rehabilitative efforts in juvenile facilities have failed and the individuals continue a life of crime.
Both federal and state courts can handle civil and criminal matters, however, many criminal cases involving federal law are tried in state courts. It's important to note that the same act can lead to prosecution at both the state and federal levels without violating the 'double jeopardy' clause of the U.S. Constitution as they represent two separate sovereignties.