The office of Los Angeles City Attorney Carmen "Nuch" Tratanich has stepped up its efforts to close unlicensed medical marijuana dispensaries, notifying landlords and operators of 140 pot shops that they must close immediately. In a letter sent Monday, the office contacted dispensaries which did not file applications to participate in a lottery to choose 100 that will be allowed to operate in the city, reports John Hoeffel at the Los Angeles Times. The city clerk received 228 applications from dispensaries and is currently reviewing them all to make sure they qualify for the drawing. To qualify, pot shops must have been in business since September 14, 2007. The city could sue violators and seek financial penalties, as well as pursue actions "to discontinue the use and padlock the property," assistant city attorney Asha Greenberg, who has overseen the enforcement efforts, warned in the letter. "The next step for us is to wait and see if these places close, and if they don't close, LAPD will investigate them, and we will take legal action against the ones that remain," Greenberg said. The city is restarting a process that first began 10 months ago when it sent warning letters to 439 dispensaries. That effort was derailed when scores of dispensaries sued, challenging the city's strict medical marijuana ordinance. A judge in December declared parts of that law unconstitutional, and the City Council adopted a new ordinance in January. The 140 dispensaries which received Monday's warning letter were identified from the earlier list, according to Greenberg. "We basically whittled it down to these that are currently open and operating, which doesn't mean that there aren't more out there," she said. "We keep getting information that places have reopened or new ones have opened up.