If found liable, Walgreens, which is one of the country's largest pharmacy chains with over 8,000 pharmacies across the U.S., could face civil penalties of up to $80,850 for each unlawful prescription, the Justice Department said in a statement.

The Department of Justice sued pharmacy giant Walgreens for allegedly dispensing millions of unlawful prescriptions. Walgreens from August 2012 until the present "knowingly" filled those prescriptions, which "lacked a legitimate medical purpose, were not valid, and/or were not issued in the usual course of professional practice," the DOJ said.

The U.S. Department of Justice has filed a lawsuit against Walgreens Boots Alliance (NASDAQ:WBA) in Illinois federal court for dispensing millions of unlawful prescriptions over a 12-year period, driving Walgreens (NASDAQ:WBA) shares sharply lower in after-hours trading.

The Deerfield-based pharmacy giant plans to close as many as 1,200 in the coming years, with 5 Chicago stores on the latest list.

Walgreens will close five Chicago stores next month, part of the Deerfield-based pharmacy chain’s plan to shutter 1,200 locations by 2027.

Walgreens is closing five stores in Chicago next month as part of its strategy to revitalize its struggling business. Last October, the drugstore chain announced that it would be closing 1,200 stores in the United States over three years.

Walgreens’ plan to combat increasing theft by locking products up at their stores has hurt sales, the company’s CEO said in a recent earnings call.

Despite efforts to prevent retail theft, Walgreens reported a 32% in "shrink," or a loss of inventory that can’t be accounted for through sales.