"Typically with a plea like this, you wouldn't expect to receive the absolute maximum" sentence, Nash said. Nash declined to say whether Miniard still worked for Manalapan Mining.
Miniard and Davis, the operations manager, will also plead guilty to a charge that they knowingly violated a safety rule, according to the proposed plea agreements. That count carries a maximum sentence of one year.
The agreement also says Manalapan could be fined up to $250,000.
The men along with the mine's second-shift foreman, Bryant Massingale, were indicted on several charges in February. Massingale pleaded guilty in August to making a false certification and knowingly violating a safety standard. He is scheduled to be sentenced on Jan. 10.
The indictment said records of pre-shift inspections kept by the supervisors dating from June 13 to June 28 were falsified. Partin died on June 29.