A former bank teller in central Iowa is going to prison for stealing money from the bank.

The U.S. Attorney’s Office in Des Moines reports Brian Madison of West Des Moines was sentenced to 18 months in prison for bank embezzlement. He’s also been ordered to pay back the $259,000 he took from his former employer, TruBank. Investigators say the fraud was detected during a cash audit at the bank due to a corporate merger.

They say Madison embezzled the money over a nearly five-year period by moving cash from the teller drawer he used, into an unmonitored teller drawer. He then modified cash count sheets so the fraud wasn’t discovered during routine cash counts.