NYC man arrested in 'check-washing' scam that cost 2 Long Islanders $20G, police say

An unemployed Bronx man was arrested and charged in a "check-washing" scam that police said cost Suffolk County residents more than $20,000.

Suffolk police said John Dematteo, 58, was arrested earlier this month and charged with two counts of third-degree grand larceny and two counts of first-degree identity theft. Court records show Dematteo, who was represented by Legal Aid, entered a plea of not guilty to all charges Thursday before Judge James F. Leonick in First District Court in Central Islip. Those records show he was released on his own recognizance and is due back in court April 1.

The arrest, police said, followed an investigation by detectives from the Financial Crimes Unit.

According to an emailed news release detailing the arrest, police said that between August and January Dematteo washed — or cleaned details, changing the payment information on — a total of 14 checks that had been stolen while "in transit" though the U.S. Postal Service.

A dozen of the checks belonged to an 86-year-old woman from Bay Shore who lost $17,315, police said, while a 73-year-old Patchogue woman lost $3,414 from two other checks that were "washed" as part of the alleged scam.

It was not immediately clear how Dematteo acquired the checks. Police said only that U.S. Postal Service inspectors have been notified of the investigation and arrest — though it remains unclear if Dematteo was ever employed by the USPS or if he got the checks some other way.

Police are asking anyone who believes they may have been victimized by this scam to contact Financial Crimes detectives at 631-852-6821.

By John Valenti

john.valenti@newsday.com

John Valenti, a Newsday reporter since 1981, has been honored nationally by the Associated Press, Society of the Silurians and National Headliner Awards for investigative, enterprise and breaking news reporting, as well as column writing. He is the author of “Swee'pea,” about New York playground basketball star Lloyd Daniels. His debut crime novel, “For Nothing Is Hidden,” rooted in 1950s Long Island, was released in October 2025.