A New Hampshire man accused of placing razor blades and screws in pizza dough pleaded guilty Thursday to a federal charge in U.S. District Court in Portland.

Nicholas R. Mitchell, 39, of Dover was indicted by a federal grand jury in March and pleaded not guilty to two counts of tampering with a consumer product on March 29.

In a plea agreement with the U.S. attorney’s office, Mitchell pleaded guilty to the second count of the indictment that contained an allegation that he placed razor blades in pizza dough in Saco on Oct. 5.

A sentencing date has not been set.

U.S. District Judge Jon Levy ordered that Mitchell continue to be held without bail until sentencing.

Federal court documents do not identify the business but it previously was identified as a Hannaford Supermarket.

The other count accused Mitchell of placing a screw in pizza dough on Sept. 11, at the same grocery store. That count is to be dropped after Mitchell is sentenced, according to the plea agreement.

As part of the agreement, Mitchell waived his right to appeal his sentence to the First U.S. Circuit Court of Appeals in Boston if it is not longer than four years and nine months. The maximum sentence for the crime is 10 years in federal prison.

The investigation that led to Mitchell’s arrest began on Oct. 6, 2020, after three customers reported finding razor blades in packages of Portland Pie pizza dough, according to court documents. Employees subsequently searched the remaining dough and found another dough with a razor blade in it.

As a result, Hannaford, Shaw’s and Star Market grocery stores pulled all Portland Pie products from their stores in the region. Hannaford also issued a recall on all Portland Pie products purchased after Aug. 1.

While a motive for Mitchell’s crime is not outlined in federal court documents, they do say that he was fired a year ago from his job as a forklift operator for the Scarborough firm that makes pizza dough for Portland Pie.

Mitchell initially was charged in October in York County Superior Court with reckless conduct. That charge is expected to be dismissed. Under state law, he faced up to five years in prison and a fine of up to $5,000 if convicted of the reckless conduct charge.

Assistant U.S. Attorney Daniel Perry, who is prosecuting the case, and Federal Defender David Beneman, who represents Mitchell, both declined to comment on the case. It is the practice of their offices to not comment on pending cases.