ROCKLAND, Maine — The leader of a prison drug ring faces up to an additional five years of incarceration after pleading guilty Friday to one count of trafficking in Suboxone.

Paul Milardo, 42, from Cushing, agreed to a plea deal in Knox County Unified Court and is scheduled to be sentenced in December. The agreement calls for a sentencing cap of five years in prison, but the defense can argue for less time.

According to Assistant Attorney General Katie Sibley, Milardo contacted 71-year-old Douglas Mazzotta of Middletown, Connecticut, to ship Suboxone to several people in Maine who would then smuggle the drug into the prison at his request. The Suboxone strips were sealed inside cards.

Mazzotta pleaded guilty in April to trafficking in Suboxone and was given a completely suspended five-year sentence.

Milardo, who was arrested in August 2013 and later convicted of a drug-related robbery, has been serving a four-year sentence for that crime. Any sentence he gets for the new conviction will be added to the time he has left.