Tyshawn Plowden, 28, was arrested on Saturday, March 19, and charged with first-degree promoting prison contraband, a felony, police said.
Plowden was at the facility to visit an inmate, police said.
He was arraigned at the Town of Ossining Justice Court and was sent to the Westchester County Jail in lieu of $2,500 cash bail or $25,000 bond.
Police did not say what kind of a weapon Plowden is accused to taking into the maximum-security prison.
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