The statement accompanied the arrest Wednesday night of David Fresques, 25, an ex-convict with gang connections and a long history of violent criminal activity, the Salt Lake Tribune reported Thursday.
Fresques had been on the run since Tuesday, when a man and two women were shot and killed in a residence known by the city's United Police Department as a drug house. A fourth person, a woman, also was shot and hospitalized. Four other residents of the house were uninjured, the newspaper said.
Fresques was arrested on charges of aggravated murder, murder, aggravated burglary and illegal firearm possession, and a resident of the house, Jose Fernando Garcia, 38, was arrested on suspicion of obstructing justice and other charges, police said.
The probable cause statement said Fresques arrived at the house Tuesday, and after an altercation with "one of his associates," began shooting a hand gun.
A witness said Fresques "opened the door to a room where a female and (the witness) were, and shot her." The witness "heard more gunshots" as Fresques allegedly went from room to room, firing.
The United Police Department Wednesday identified the victims as Omar Paul Jarman, 35, Shontay Nichole Young, 34, and Danielle Beatrice Lucero, 26.