SALT LAKE CITY — A Utah man accused of plotting a deadly attack on a luxury outdoor shopping center in the heart of Salt Lake City this week told investigators he planned to “randomly shoot and kill people.”

Jack Harry Stiles, 42, told a crisis counselor he was preparing to “kill as many people as possible” today because it marked the anniversary of his mother’s death, authorities said.

Jail records show Stiles was booked into the Salt Lake County jail Monday and remains there on $1 million bail. The Salt Lake Legal Defender’s Office said he didn’t have an attorney yet.

Court documents show Stiles didn’t have any weapons but was planning to buy two guns with silencers and stock up on ammunition. No motive was clear, Salt Lake County District Attorney Sim Gill said.

Police first learned of the plan Aug. 12 when a West Valley police officer was dispatched to Pioneer Valley Hospital by a crisis worker. At that point, investigators began looking into Stiles’ background.

Family members told investigators the man had a history of mental illness and making threats, the district attorney said.

Gill told The Associated Press that authorities were motivated to take action by the Washington Navy Yard shooting last Monday that left a dozen people dead. That suspect had a history of violent and erratic behavior.