Following a deadly listeria outbreak in ice cream, the Justice Department is warning food companies that they could face criminal and civil penalties if they poison their customers.

“We have made a priority holding individuals and companies responsible when they fail to live up to their obligations that they have to protect the safety of the food that all of us eat,” Associate Attorney General Stuart Delery said in an interview with The Associated Press.

After years of relative inactivity, the administration has stepped up criminal enforcement on safety cases. In the most high-profile case, a federal court in Georgia last year found an executive for the Peanut Corporation of America guilty of conspiracy, obstruction of justice, wire fraud and other crimes after his company shipped out salmonella-tainted peanuts that sickened more than 700 and killed nine in 2008 and 2009.

Delery, the No. 3 official at the Justice Department, wouldn’t say whether the government plans to pursue charges against Texas-based Blue Bell Creameries, which recalled all its products and shut down production earlier this year after listeria in the company’s ice cream was linked to illnesses and three deaths. A Food and Drug Administration investigation found that Blue Bell knew that it had listeria in one of its plants for almost two years before the recall.

Other recent actions prompted by the Justice Department during the Obama administration:

— A 2013 guilty plea from Colorado brothers who grew and sold listeria-tainted cantaloupe that killed more than 30 people in 2011.

— A 2014 plea deal, resulting in prison time and millions of dollars in fines, between the government and an Iowa egg company and its executives. An outbreak of salmonella linked to the eggs sickened almost 2,000 people in 2010.

— A May 2015 settlement with ConAgra Foods for $11.2 million after the company shipped Peter Pan peanut butter tainted with salmonella from a plant in Georgia, sickening more than 600 people in 2006. That sum includes the highest criminal fine in a U.S. food safety case.

Bill Marler, a food safety lawyer who has represented victims in many of those cases, says Justice’s recent activity is especially notable because in many of the cases, company executives didn’t know they were shipping out tainted food, but they were hit with criminal charges anyway.

“It’s been very much of a sea change,” Marler said. “Once you start down this road you have to decide whether you are going to do it all the time or selectively.”