A man has pleaded guilty to a federal crime for putting razor blades in pizza dough sold at Hannaford stores in Maine last year.

A federal grand jury indicted Nicholas R. Mitchell in March on two counts of tampering with a consumer product. He pleaded guilty to one of those counts Thursday during a video hearing in the U.S. District Court of Portland.

A booking photo released Oct. 12, 2020, by the Dover, N.H., Police Department shows Nicholas Mitchell of Dover, accused of putting razor blades in pizza dough sold on Oct. 5 at a Hannaford supermarket in Saco, Maine. AP

As part of a plea agreement filed in court, Mitchell will accept a sentence of up to 4 years and nine months in prison. The penalty for the tampering charge could otherwise be up to 10 years, and if the judge imposes a longer sentence, Mitchell would have the right to appeal.

The sentencing hearing has not yet been scheduled.

“Do you plead guilty to the charge in this case because you are actually guilty?” District Judge Jon Levy asked during the Thursday hearing.

“Yes, sir,” Mitchell said.

There were no reports of injuries or illnesses from the tampering. But the case drew attention to gaps in food security practices after both Hannaford and the pizza dough maker revealed they had received similar reports of problems with pizza dough in the two previous months but had not immediately notified customers, police or food safety regulators.

Erica Dodge, a spokeswoman for Hannaford, said Thursday that the company has worked closely with the state and improved its internal incident reporting process in response to this incident.

“We have appreciated the collaboration and partnership with area law enforcement and are grateful for their diligence and perseverance during the investigation into the malicious food tampering incidents,” Dodge said. “Their work led to the successful prosecution and resolution of this case. We appreciate as well their recognition of the Hannaford associates who worked closely with them in this investigation.”

Mitchell, 39, was arrested in October after police in Saco, Sanford and Dover, New Hampshire, began investigating reports that customers had found razor blades and metal fragments in Portland Pie Co. pizza dough sold at Hannaford supermarkets.

He was initially charged in state court with reckless conduct with a dangerous weapon and violating the conditions of his release, which prohibited him from engaging in new criminal conduct or possessing dangerous weapons, including razor blades. The state charges will be dismissed now that he has pleaded guilty to the same conduct in federal court.

At the time, Saco police said they were sharing information about their investigation with federal authorities. It is a federal crime to tamper with food products in a way that affects interstate commerce, even if no one is sickened or harmed. Mitchell has been in jail since his arrest, and he originally pleaded not guilty to the two federal charges.

The government will ask for certain reductions in sentencing as part of the plea agreement. Court documents include the prosecution’s version of the tampering, which Mitchell did not contest.

“Had the case proceeded to trial, the government would produce evidence that would establish beyond a reasonable doubt that on October 5, 2020, this defendant knowingly tampered with pizza dough by placing razor blades into the dough that was sold to consumers at a Saco supermarket,” that document says.

Mitchell had been fired last summer from his job as a forklift operator for It’ll Be Pizza, the Scarborough company that manufactures pizza doughs to be sold in Hannaford and other grocery stores.

After pizza dough was returned to the Saco Hannaford last October with metal blades in it, surveillance video showed Mitchell had entered the store on Oct. 5 and gone directly to the refrigerated case of pizza dough. He handled multiple doughs and remained near the case for seven minutes, and then left the store without stopping or buying anything. Mitchell was the only person near the case for an extended period that day.

“Three patrons purchased pizza doughs within a couple of hours of the defendant’s activity at the refrigerator case,” the document says. “When the patrons subsequently opened the pizza dough, they discovered razor blades secreted inside the pizza dough.”

Store personnel removed the unsold dough and found another with a razor blade inside.

After the contaminated dough was found in Saco in October, Hannaford issued a product recall for all Portland Pie dough and cheese products sold at its 184 stores in New York, Massachusetts, Vermont, New Hampshire and Maine. The recall was later expanded to Shaw’s and Star Market stores in five states.

Hannaford employees had been notified in August about a similar problem with pizza dough sold at its Sanford store, but the company did not alert customers, police or health officials in that case until after police began investigating the Saco incident two months later.

The grocery chain provided a statement at the time blaming the failure to inform customers or police in August to a technology fault in their internal reporting system. Hannaford apologized and promised to add more safeguards to that system. The state investigated last year what was an apparent violation of the section of the Maine Food Code that requires licensed grocers to report imminent health hazards. A spokesman from the Maine Department of Agriculture, Conservation and Forestry could not be reached Thursday but said in March that the grocery chain had made changes.

It wasn’t clear whether Mitchell was living in Sanford or Dover, New Hampshire, at the time of his arrest. Federal and state court documents are inconsistent.