A retired NYPD sergeant with no prior criminal record was arrested yesterday just minutes after robbing a Long Island bank. Thomas Feeney, 47, who retired 12 years ago because of knee injures and a heart condition, allegedly walked into a Huntington Station bank Tuesday morning and passed the teller a note demanding cash and calling attention to the loaded .38-caliber pistol tucked in his waistband. He walked out with an undisclosed sum, but one brave bank employee trailed him to his SUV and phoned in his license plate to police, who pulled him over just a couple miles away. Besides the gun and the cash, cops found a badge noting he was a retired NYPD officer in his pocket (but arrested him anyway!). Sgt. Robert Doyle of the Major Case Investigations Unit tells Newsday, "He said he'd been out so long that he doesn't get much money in disability anymore." Apparently, Feeney's got credit card debt in the five figure range, and Doyle tells the Post the bank job "appears to be economically motivated." But let's not rule out thirst for adventure as a motive, either.