(CNN) -- A 42-year-old Utah man planned to "randomly shoot and kill" at a Salt Lake City mall, then pick off moviegoers, and finally blow up a city bus -- a plot he detailed to a counselor who alerted police -- according to a court document.
Jack Harry Stiles has been charged with allegedly making a terrorist threat involving the use of a hoax and a real "weapon of mass destruction" as defined under Utah law, according to the charging document obtained Tuesday by CNN from the Salt Lake County District Attorney's Office.
The Salt Lake Public Defender's Office acknowledged Tuesday that it is representing Stiles, but declined otherwise to speak about his case.
According to the charging document, police first became aware of the plot after an employee at Pioneer Valley Hospital in West Valley City told them August 12 how Stiles detailed plans to "kill as many people as possible." The document did not state why Stiles was at the hospital, identifying the woman he spoke with as a "crisis worker."
The attack was to unfold Wednesday, which is the anniversary of Stiles' mother's death.
After the hospital worker, Stiles allegedly himself then spoke to authorities. He specified three targets he had "mapped out" to determine the best places to hide in order to inflict the most bloodshed, the charging document states.
Stiles explained he'd carry bags containing two automatic handguns with silencers, as well as five extra magazines of ammunition per gun, authorities say. The document did not state whether he had allegedly obtained any of those.
"He talked about going out and procuring these weapons," Salt Lake County District Attorney Sim Gill told CNN affiliate KSL. "Or if he couldn't do it, then he certainly knew somebody who was sympathetic to him who would help him."
The charging document does not specify others involved in the plot, nor is anyone else known to have been arrested in connection to it.
Stiles' first stop: the City Creek Center mall in downtown Salt Lake City. Opened in March 2012, this shopping mall features restaurants and more than 100 stores such as Nordstrom, Macy's, Tiffany & Co., Michael Kors and Coach, according to its website.
Having already gone there "observing people," Stiles said he planned to go back around lunch time September 25 and "just randomly shoot and kill people," the charging document says.
His next stop, he told investigators, would be about 5 miles south at the Sugarhouse Movies 10 complex. Stiles allegedly had done his homework there as well, claiming it had slow-moving crowds and no security system and expressing concerns moviegoers might scramble if he went during a busier time.
The charging document states that his idea was to take up a position in the back of the theater and start selectively "shooting people's heads off" with handguns.
Lastly, Stiles said he wanted to plant a bomb under a public bus to detonate as it moved over the City Creek Center bridge "to cause mass amount of death," according to the court document.
"The defendant indicated he will not intentionally shoot and kill children," the charging document says about Stiles' alleged intentions overall. "However, the defendant said he will randomly kill people until he runs out of ammunition."
Either that or police get to him. If that happens, according to the document, the suspect planned to "drop his guns, place his hands in the air and surrender because the police are 'faster shots.'"
Asked Tuesday about the plot, the Utah Transit Authority referred inquiries to the Salt Lake City Police Department. Linda Wardell, general manager of City Creek Center, declined to detail the security measures being taken there.
"The safety of our shoppers and our employees is our top priority every day," Wardell said.
Stiles -- who, according to KSL and other media, was charged Monday -- is being held on $1 million bail, another court document states.