It happened at the UPS facility on Foster Avenue in Canarsie around 11:15 p.m. Monday.
Police said the would-be robber, 38-year-old Martin Peters, attempted to rob the armed security guard, who also happened to be a retired police officer with the NYPD.
The guard shot the man in the foot. He was then transported to Brookdale University Medical Center with a non-life threatening injury.
Peters is charged with menacing, trespassing and weapons possession.
The security guard is not facing any charges.
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