AUGUSTA — A Saco woman will spend 2½ years in prison after pleading guilty Thursday to robbing three pharmacies in three Maine cities over 15 days last summer.

Randa Lee Nason, 24, targeted CVS pharmacies in Augusta, Waterville and Biddeford in her quest for the drug OxyContin.

At each site, she handed a pharmacy worker a note saying, “Give me all your OxyContin. My boyfriend is in the store with a gun.”

The employees complied. She was arrested in July.

Justice Robert Murray sentenced her to 10 years in prison, with all but 30 months suspended, and four years’ probation. She is ordered to possess no alcohol or illegal drugs. Conditions of her probation ban her from entering any pharmacy in Maine.

At the same hearing in Kennebec County Superior Court on Thursday, Nason pleaded guilty to several misdemeanor offenses, all from Biddeford, which included two counts each of assault and violating conditions of release and one count of operating after suspension.

Fines from those offenses total $850; the jail time is concurrent to the prison sentence.

Assistant District Attorney James Mitchell Jr. outlined the crimes:

• The Biddeford robbery was first, on June 25, 2010, in which Nason got more than 400 Oxycodone pills, the generic version of OxyContin;

• The Waterville robbery was next, on June 30, 2010;

• The Augusta robbery took place July 10, 2010.

Surveillance footage from the pharmacies and nearby stores led to the identification of Nason, Mitchell said. Police found her fingerprints on the note used in the Waterville store.

Also, in the Augusta robbery, Nason wore a distinctive hat that was found in the vehicle when she was stopped.

In exchange for the guilty pleas, the judge dismissed two counts of aggravated trafficking in scheduled drugs related to the Augusta and Waterville robberies.