Need information on the american legal system. Need research for novel.?

Every state has different laws.Your best bet would be to interview a public defender or district attorney. People stay there for different periods of time based on the severity of the crime. Yes, they could be sent for stealing. No, a parent cannot put their child into juvenile detention. Juvenile detention is JAIL for persons under the age of 18. Yes, there would be sentencing, as that is when the judge determines how long the minor will be encarcerated. There are different levels of security just as there is with adult jail, from minimum security to maxi-max where children are in lock down for 23 hours daily. Google juvenile detention centers as Im sure you will find some good info. Good luck, and if you get published...I get a copy! :)