PORTLAND  — The man who put small businesses on edge last spring with a string of armed robberies and attempted robberies will serve nearly six years in prison.

Travis Card, 38, was arrested in April in the wake of more than a dozen unsolved holdups in southern Maine. He pleaded guilty in August in federal court for interfering or attempting to interfere with commerce by robbery at 11 businesses from Old Orchard Beach to Cumberland.

U.S. District Judge Nancy Torresen sentenced him Wednesday to 70 months in prison, followed by three years of supervised release. He will also pay restitution for his gains from the robberies — slightly less than $3,000.

A memo filed in court last month stated for the first time that opioid addiction led Card to commit the crimes, and the judge on Wednesday encouraged him to seek treatment both in prison and upon his release.

“This case is a string of, really, tragedies from many levels,” Torresen said. “The system really has not evolved to the point where it’s good at dealing with the opiate crisis that we’re faced with.”

But she refused a request by the defense attorney for a lesser sentence of 60 months, citing in part the statement of a teenage victim who was working the reigster when Card robbed a Westbrook coffee shop. The judge noted that the weapon turned out to be a pellet gun, but the victims believed it to be a real firearm.

Your crimes are not really serious because you took a lot of money,” Torresen said. “Your crimes are serious because you involved a lot of fear.”

Among the charges Card was convicted of included robbing the China Eatery on March 29 and attempted to rob of Moby Dick Variety on April 11, both in Old Orchard Beach.