54-year-old Caroline Richardson is already serving time for tax evasion.  On Monday morning she pleaded guilty to stealing the $4.1 million on which she didn't pay taxes.

Richardson is scheduled to be sentenced March 18. She's already serving a five-year term. 

Prosecutors say Richardson stole from Omaha-based Colombo Candy and Tobacco in 2010 and 2011 while working as company controller. Prosecutors say she used the money to gamble at Ameristar Casino in Council Bluffs. 

Colombo has sued Ameristar, saying the casino knew about Richardson's job and her approximate salary and should have known Richardson was gambling with ill-gotten money.