Greenwich police said they arrested a person who stole $175,000 worth of jewelry from Tiffany & Co. on Greenwich Avenue, on Saturday.
Police said 19-year-old Edgardo Bautista-Gallardo flashed a gun and threatened to shoot the security guard and employees if they didn't hand over the jewelry.
Police said Gallardo was carrying the jewelry, a gun and a BB gun.
Gallardo is being held on a $750,000 bond.