A 57-year-old drug addict was sentenced to 15 years in prison this week after admitting he robbed a series of drugstores to get a prescription painkiller.

On Feb. 10, 2012, a man later identified as Robert Federico Gutierrez went into the Walmart on West Valencia Road, handed the clerk a note demanding $2,000 and implied he had a gun.

The clerk handed the note back to Gutierrez, told him "No" and walked away, according to court documents.

Less than three hours later, Gutierrez handed a West Ajo Way Walgreens pharmacy technician a note demanding oxycodone and showed her a gun, according to court records. Gutierrez waited while the technician got the pharmacist. The pharmacist gave Gutierrez oxycodone after, he, too, was threatened with the gun.

On March 6, Gutierrez handed a similar note to a Walgreens pharmacy technician on East Irvington Road, but the technician just walked away.

A pharmacist at a Walgreens on North Oracle Road gave Gutierrez oxycodone on March 6 and May 30 after Gutierrez threatened him with a gun.

Gutierrez was identified as the robber by his girlfriend, an associate and someone who called 88-CRIME. He was also picked out of photo lineups by four victims.

Gutierrez pleaded guilty to three counts of armed robbery in exchange for other counts being dismissed.

Pima County Superior Court Judge Paul Tang sentenced Gutierrez to three concurrent terms of 15 years.

Gutierrez told a probation officer he became addicted to oxycodone after hurting his shoulder doing masonry work. He had six prior felony and four prior misdemeanor convictions.

Contact reporter Kim Smith at 573-4241 or kimsmith@azstarnet.com