Authorities say say Marian Serban installed the device and a video camera at Astoria Federal Savings banks in Kings Park and Huntington Station.
They say he stole $9,700 from 13 people and gained access to the financial information of 25 accounts.
Serban, 43, resides in Romania and has been known to stay at various hotels when in the United States. He has previously traveled to Miami, Florida and Las Vegas, Nevada.
He is charged with grand larceny and identity theft.