A woman convicted of murdering her University of Arizona dorm mate by stabbing her 23 times was sentenced Tuesday to life in prison with no possibility of parole.

Galareka Harrison, 19, was convicted Sept. 19 in the 2007 slaying of 18-year-old Mia Henderson, a fellow member of the Navajo Nation from northern Arizona. Both were freshmen.

Prosecutors didn't seek the death penalty.

Superior Court Judge Nanette Warner heard four hours of testimony Monday from relatives of both women giving factors to be taken into account at the sentencing.

"You killed in a very violent way — there's just no way around that," she told Harrison on Tuesday.

Prosecutor Rick Unklesbay said Harrison had planned the killing for days after Henderson, from Tuba City, accused her of stealing her student ID charge card, a Social Security card, checks and $500 from a bank account.

He noted that on a trip home to Chinle and back to school with another student before the stabbing, Harrison spoke of having a friend who was discussing suicide and asked whether fingerprints could be detected through gloves. Witnesses testified Harrison bought an 8-inch kitchen knife on that trip.

Back at the university, she composed a fake suicide note purporting to be from Henderson, checked to see if Henderson had fallen asleep in their dorm room and then spent time "thinking and thinking and thinking and thinking" before she attacked on Sept. 5, 2007, Unklesbay said.

Harrison's attorney, assistant Public Defender John O'Brien, called the killing "a crime of passion" and said: "Galareka is truly, truly sorry for the pain that she has caused."

In a soft, halting voice, Harrison said: "I just want everybody to know that we all suffered from this."

Harrison also was found guilty of three forgery counts and one count of identity theft. Warner sentenced Harrison to 2 1/2 years for each of those counts, to be served concurrently with the life sentence.

Unklesbay said Henderson's family will never get over the pain of her loss but will have a sense of relief in knowing that "Miss Harrison will never get out of prison ... and that she's where she deserves to be."