Chief Keef was taken into custody today after a two-hour hearing in Cook County juvenile court, the Chicago Sun Times reports. Judge Carl Anthony Walker ruled that Keef had violated the terms of his 18-month probation, stemming from a December 2011 arrest for unlawful use of a weapon. Prosecutors said Keef violated his probation in June, when he visited a gun range in New York to film a since-retracted episode of Pitchfork's Selector series. (A judge ordered Pitchfork to surrender video from the episode to prosecutors last year.) Keef will be held until a sentencing hearing, scheduled for Thursday.