The Juvie Three - by Gordon Korman

Douglas Healy has set up a halfway house for a few juvenile delinquents. All three of the boys, Gecko, Terrance and Arjay, were convicted of crimes based on shaky evidence. Healy thinks that he can assimilate them back into society and help them get their lives in order. One night, while trying to stop the boys from going out after curfew, Healy is knocked off of a second story fire escape. He is taken to the hospital as a "John Doe". It is up to the boys to lay low and do exactly as they are supposed to in order to keep the caseworker from visiting and discovering their secret. They file Healy's reports to the court, infiltrate the hospital in which Healy is being treated (he is unconscious), and behave well enough to keep the nosy neighbors away - for now.