"No adjectives exist to adequately describe this heinous atrocity," Wiseman said. "This act is shocking and utterly abhorrent for a civilized society."
The judge rejected a plea by Arnold's attorneys for a minimum sentence of life in prison with the chance of parole after 25 years. A jury last week spared Arnold the death penalty when it couldn't reach a consensus.
"I am innocent of these charges," Arnold said in a statement read by her attorney, Jon Paul Rion.
Arnold was convicted Aug. 29 of aggravated murder in the death of month-old Paris Talley in 2005. Prosecutors said she intentionally put her baby in the microwave after a fight with her boyfriend. The couple had argued over whether the boyfriend was the biological father.
It was Arnold's second trial. Her first ended in a mistrial when new witnesses surfaced.
Rion has asked for a third trial, saying a former cellmate who said Arnold confessed has now changed her story. Rion said he's also found additional witnesses who point to someone else being responsible for killing the baby.
The judge hasn't ruled on the motion for a new trial.
Rion said Arnold loved her baby "with all of her heart and more" and regrets drinking the night of her baby's death to the point of not remembering what happened.
"We have a mother who has lost her own daughter," Rion said. "That will plague her and follow her like a shadow for the rest of her life and into the next."
Prosecutor David Franceschelli told Wiseman that Arnold has shown no genuine remorse.
"The only remorse here is she got caught," Franceschelli said.