Cook County sheriff's police about 2:15 p.m. Saturday saw 31-year-old Ronald Reed holding an open beer can on a Green Line train near the Austin station, the sheriff's office said.
He was taken into custody for disorderly conduct.
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While searching him, police found a machete with an 18-inch blade in a sling on his back, as well as a knife with a 5-inch serrated blade in a holster, the office said.
Reed has been charged with unlawful possession of a weapon.
He appeared in court Sunday and was ordered detained in Cook County Jail.
The Cook County Sheriff's Office posted video of the arrest.