Characterizing a string of foodborne illness outbreaks as an “unfortunate set of events,” Chipotle Mexican Grill’s founder Steve Ells reported the chain’s net income dropped 44 percent in the last quarter of 2015. Ells’ co-CEO Montgomery Moran revealed more bad news yesterday during the Denver company’s quarterly earnings conference call — the Department of Justice is expanding its criminal investigation of the chain that was spurred by a norovirus outbreak at a Simi Valley, Calif., location.