The number of kids sent to youth prison from Cook County declined dramatically between 1997 and 2004. According to a new report out today from the Annie E. Casey Foundation, that's thanks to a cluster of reforms that divert youth away from pretrial detention and into more community-oriented forms of supervision. Jeffrey Butts is a research fellow at the University of Chicago's Chapin Hall Center for Children. He's looked at the numbers behind the report, and done some crunching of his own. He says policy reforms are only part of the reason for the decrease.