Authorities said a man attempted to enter the locked side door of the Hommocks Middle School Thursday morning.
Police said the man asked to retrieve an item he left in the pool over the weekend.
A staff member noticed what appeared to be a gun in his waistband, officials said. He asked the man if he had a gun and the man replied yes, and stated he worked in the security field.
The man was told he was not allowed to be on school property with a weapon and left immediately.
Police were called and responded immediately. Police have been dispatched to all four schools. Parents were asked not come to pick up their children until the end of the school day.
The campus employee he spoke with described the interaction as pleasant. Police are looking to speak with the individual.
He was wearing a black North Face jacket, he is about 5 feet 8 inches tall and speaks with an Irish accent.
All afternoon and evening activities at all of Mamaroneck schools were canceled on Thursday.
The district said it plans to have a police presence at schools for the start of the day on Friday.
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