On a hazy Southern California morning, undercover police officers watched Jiayong Yu step out of a Range Rover in a strip-mall parking lot and walk into a Chase bank with a black-leather backpack full of cash.
At the teller window, Yu pulled out stacks of bills and waited while a woman fed them into a cash-counting machine. After Yu left, an officer asked the teller if he had deposited more than $10,000, the threshold requiring banks to flag transactions to federal regulators.
More like $100,000, the teller said. By then, Yu was already on his way to Chase and Bank of America branches in Claremont, Calif., about 35 miles away.
Federal authorities allege that Yu worked for an underground banking network that bought dollars at a discount from Mexico’s Sinaloa drug cartel and sold them at a premium, largely to Chinese nationals in the U.S.
