A Rockland County man was arrested within hours of the discovery of a break-in at the Sag Harbor Variety Store at 114 Main Street in the village Saturday morning.The rear glass door, which faces the municipal parking lot, was found smashed at about 7:30 a.m. A brick had been thrown through it, village police said. Lisa Field, the store’s owner, reported that two Sharp ER-A320 cash registers with $160 in cash in each of them were stolen.State police were called in to help investigate the burglary because the village’s Police Department is without a detective. State police brought in forensic and investigative teams to process the crime scene.Police then received information about who was responsible for the break-in, and officers nabbed Patrick J. Helmer, 35, on Main Street, not far from the Variety Store, at 10:45 a.m. He had $335 in cash on him in denominations fitting the description of the cash from the registers, village police said.The cash registers were found in two Dumpsters nearby. It was unclear if they were damaged. The registers cost nearly $500 each.Mr. Helmer was charged with third-degree burglary and third-degree criminal mischief, both felonies, criminal possession of stolen property in the fifth degree, possession of burglary tools, and petty larceny, all misdemeanors. Sag Harbor Village Justice Lisa R. Rana arraigned him on Sunday. He is being held on $12,000 cash bail or $24,000 bond.State police declined to release further information because Mr. Helmer’s case had not yet been presented to a Suffolk grand jury.