An arrest warrant issued by Judge Marilena Chessa in Milan said the teenager, whose name was not released, represented a "very high and concrete danger to the community."
The youth nicknamed himself "the young Vallanzasca" after a notorious gangster from the 1970s, Italy's ANSA news service said.
The arrest warrant alleges the boy was behind a robbery spree that began six months ago when he turned 14.
He was arrested in a foot pursuit with officers that ended when he tried to jump from a third-story balcony.
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