Authorities said the owners of Columbia Liquors concocted an elaborate scheme to skip paying taxes on alcohol purchased for their Hammond, Ind., store and then sold for millions in cash to Illinois stores from a backdoor register. According to a civil forfeiture case in the Northern District of Indiana, the government says Sam and Dipti Patel bought large amounts of alcohol and then sold most of it to 17 liquor stores in Illinois, including five that they owned. Records show the front door register used for normal retail sales at Columbia Liquors averaged about $1,500 a day in sales.