What are the highlights of the article? The article is behind a paywall.
Nothing in there specifically indicates why it's being considered a "crime of passion," unfortunately--lots of the same info that we've seen in other media outlets. Excerpt below, though:
"Art Bettge, the mayor of Moscow, Idaho, said in an interview that the authorities were still investigating what had transpired but that the case was being treated as a homicide. He said the authorities did not believe that there was a “perceivable danger to the broader public,” but declined to say how the victims were killed or whether a suspect was at large.
“With a crime of this magnitude, it’s very difficult to work through,” Mr. Bettge said, adding that the police needed time to piece together what had transpired.
The authorities said they responded to a call about an “unconscious individual” on Sunday and discovered four dead people at a house near the University of Idaho campus. On Monday, they identified the victims as Ethan Chapin, 20, of Conway, Wash.; Madison Mogen, 21, of Coeur d’Alene, Idaho; Xana Kernodle, 20, of Avondale, Ariz.; and Kaylee GonCalves, 21, of Rathdrum, Idaho."