"These are difficult crimes to put together, and difficult crimes to prosecute," Gill said. "When you look at them in isolation, sometimes you have nothing more than allegations of one person against another person."
Unified Police Department detectives first came to Gill's office with a case against Peterson approximately three months ago, Gill said.
After UPD investigators became aware of allegations against Peterson, they tapped into a number of databases, including the two most used by Salt Lake County law enforcement. They saw Peterson's name in police reports in various jurisdictions, including West Jordan and Salt Lake City.
"What started out as a difficult case when we were [first] looking at it, turned into another case and a third case and a fourth case," Gill said. "All of a sudden, certain patterns started to emerge."
As it happened, Peterson met all four of the alleged victims in Salt Lake County, even though two of the alleged rapes occurred at the Heber cabin.
"This really highlights why it would be nice to have a single database system where you can log in sex crimes," Gill said. "It was fortuitous for us that we have all of our victims from the same county."
In total, Gill's office filed 25 felony charges against the 37-year-old Peterson.
According to documents filed in 3rd District Court:
• In March 2011, Peterson drove a woman he met at a church activity in Draper to his cabin in Heber, when she had only agreed to go with him to a movie. During the drive, Peterson told the woman he had a concealed weapons permit and pointed to the center console of his car where he reportedly kept a gun. At the cabin, Peterson assaulted and raped the woman.
• In July 2011, Peterson took a woman to a movie in Sandy. He later asked her to go out to dinner, but instead drove to the Heber cabin and raped her. The woman said he threatened to have her deported for an expired visa. The next day he forced her to go to his mother's house in Lewiston, where he continued to sexually assault her over the next two days.
• In December 2011, Peterson was supposed to go on a lunch date with a woman he met through an online dating site. Peterson walked into her West Jordan home, pushed her onto the couch and sexually assaulted her after she told him to stop.
• On April 21, 2012, Peterson again met with a woman he met through a dating website. He pushed her down on the bed in her Salt Lake City home and grabbed her. After a struggle, the woman managed to get him out of her house.
Gill said he reviewed a fifth woman's case involving allegations from August 2009 but declined to prosecute because he could not prove that she didn't consent to having sex with Peterson. The fifth woman, Gill said, told Peterson she "felt uncomfortable and that was the only thing she said."
Peterson, of Orem, is a certified financial planner and the owner of Peterson Wealth Management and Smartstocks.com, an online trading website. He holds an MBA in finance and entrepreneurship from Brigham Young University.
He has also been a fixture at Utah Republican events.
Peterson organized the Rocky Mountain Conservatives Convention and Barbecue two years ago at his Heber cabin as a way to make peace in the party after a bitter U.S. Senate fight between Tim Bridgewater and Mike Lee, the eventual winner.
The event was also held in 2011 and again this year, when Peterson touted it as the "CPAC of the West," referring to the national Conservative Political Action Committee that annually draws thousands of activists to Washington, D.C.
Prominent Utah politicians, including Sen. Orrin Hatch, Gov. Gary Herbert, Rep. Jason Chaffetz and congressional candidate Mia Love, have attended the event, which this year featured a debate between attorney general candidates John Swallow and Sean Reyes at Wasatch High and a keynote address by Lee.
Peterson's Facebook page featured several photos of him with Republican presidential candidate Mitt Romney, Florida Sen. Marco Rubio, Texas Rep. Ron Paul and South Carolina Sen. Jim DeMint. Peterson has billed himself as a "close personal friend of the Romney family," a claim that Chaffetz said he doubts.
Peterson remained in the Salt Lake County jail Friday with bail set at $750,000.
Defense attorney Jerry Salcido said Friday he hopes to have that amount reduced when Peterson makes his first court appearance on Monday in 3rd District Court.
"In the coming weeks there is going to be a lot of information that sheds some light on what is really going on here," Salcido said. "There is a lot of evidence that is going to change people's minds about this."
Police and prosecutors said no new allegations have arisen since Peterson's arrest became public.
"We hope there aren't any other victims," Gill said Friday. "But if there are ... they're not alone."
Tribune reporters Nate Carlisle and Robert Gehrke contributed to this report.