Boston transit police say a man who slipped through turnstiles behind another customer to avoid paying the $2.10 fare had nearly $7,000 in cash on him.
Police say they stopped 35-year-old Timothy Chapman, of Woburn, Massachusetts, at the Back Bay station after they watched him engage in what's known as piggybacking by closely trailing a paying customer.
Officers preparing to ticket Chapman took him into custody after learning there was a warrant for his arrest on unspecified motor vehicle violations.
Police say that while processing Chapman on Thursday afternoon, they found he was carrying the large amount of cash.
It wasn't immediately clear whether Chapman had a lawyer who could comment on the accusations.