LOS ANGELES (AP) — Two 22-year-old men fatally stabbed a University of California, Los Angeles student before setting her apartment on fire, prosecutors said Tuesday.

The two men pleaded not guilty in the death of Andrea Del Vesco, 21, whose body was discovered in the fire in her Westwood apartment last week. Authorities had not previously said whether she died in the fire or was killed first.

Del Vesco, who went by “Andy,” was a fourth-year psychology major and sorority member from Austin, Texas, who was going to UCLA.

Prosecutors say Alberto Hinojosa Medina of Fresno burglarized an apartment on Sept. 21, then entered another apartment and fatally stabbed Del Vesco before setting the fire. He’s charged with capital murder, arson and burglary. A judge ordered him held without bail. Prosecutors said they would decide later whether to seek the death penalty for him.

Another UCLA student, Eric Marquez, is charged with murder and burglary. He was ordered held on $1.1 million bail and faces a maximum sentence of life in prison.

Police did not give specifics on what led them to the two men, but they said it was a combination of physical evidence and witness statements.

“There’s a considerable amount of forensic evidence,” LAPD Chief Charlie Beck said, according to City News Service.