A University of Arizona student was convicted on Friday of first-degree murder in the stabbing death of her roommate last September, and now faces a sentence of life in prison, the Associated Press reported.

The jury in Pima County Superior Court deliberated for just three and a half hours before convicting the student, Galareka Harrison, of stabbing the roommate, Mia Henderson, 23 times. Ms. Harrison could be eligible for parole in 25 years.

Prosecutors, who declined to seek the death penalty, said Ms. Harrison had spent days planning the attack, including purchasing the murder weapon and writing a fake suicide note that was to have been found with the body. The violence followed Ms. Henderson’s complaint to university officials that Ms. Harrison had stolen her student ID card, her Social Security card, and checks and cash.

Still pending is a civil lawsuit in which the family of Ms. Henderson has accused the university of not dealing promptly with the roommate feud before it ended in violence.

By coincidence, also on Friday, the mother of a student at Indiana University-Purdue University at Fort Wayne was sentenced to 60 years in prison for killing one of her daughter’s roommates last April, according to The Journal Gazette, a local newspaper.

Court documents said the mother, Tina Loraine Morris, had become enraged over something she thought the victim, Liette Martinez, had said to her daughter. Shortly after the murder, Ms. Morris was arrested while driving Ms. Martinez’s car and confessed. —Andrew Mytelka