A Plymouth paramedic will serve six months in a workhouse and five years’ probation after he admitted to stealing painkillers meant for patients.

Robert Ryan Lien, 37, said in court that he was “100 percent” guilty of taking the drugs while working for the North Memorial Ambulance Service, according to the Hennepin County attorney’s office. He pleaded guilty to eight counts of theft of controlled substances on three occasions while working as a paramedic.

According to the criminal complaint, Lien took a bag of the powerful painkiller Dilaudid and replaced some of it with liquid saline around Christmas 2015. Later on Dec. 30, a supervisor found two vials from a pouch used by Lien that may have also been filled with saline.

The next night, Lien went into the North Memorial Ambulance Service building and stole several vials of painkillers, including Dilaudid and fentanyl. Lien later admitted to co-workers that he took the drugs home and used them for himself.

During Lien’s sentencing, Judge Jeannice Reding mentioned the seriousness of his crimes and said she was disturbed by his use of saline as substitute. She said Lien was fortunate it did not result in injury to a suffering patient, according to the Hennepin County attorney’s office.

As part of his sentence, Lien must also pay at least $1,000 in fines. If he fails to complete his probation, Lien could be sentenced to up to 15 months in prison and $5,000. If he successfully completes probation, then his felony charge will be reduced to a misdemeanor.