Before Las Vegas mass shooting, a friend of the gunman implored him not to 'shoot or kill innocent people'

(CNN) — A friend of Stephen Paddock, who carried out the deadliest mass shooting in modern US history in Las Vegas in 2017, said in letters that he was concerned about Paddock committing a shooting and asked him not to "shoot or kill innocent people," according to writings obtained by the Las Vegas Review-Journal.

Ten letters, which were obtained through a public records request, were "found in late November 2017 by the new owners of an abandoned office building in Mesquite, Texas," according to FBI records, the newspaper reported. CNN has requested the records.

"I can get someone for you who can help you," Jim Nixon, Paddock's friend, wrote in a letter dated May 27, 2017, according to the newspaper. "Please don't go out shooting or hurting people who did nothing to you. I am concern [sic] about the way you are talking and believe you are going to do something very bad. Steve please please don't do what I think you are going to do."

In October 2017, Paddock opened fire on a massive crowd of concertgoers from a window of the Mandalay Bay Resort and Casino, killing 58 people in the initial shooting and injuring about 500 others. In the years after the massacre, two more victims have /died of shooting-related injuries.

Paddock sent nine of the letters to Nixon between 2013 and June 2017, according to the report.None were shared in their entirety by the Review-Journal.

Nixon told CNN he exchanged letters with Paddock about two or three times a year.

They first met "around 2010 or 2011" in Virginia and developed a "good relationship," he said. Nixon said after they became acquainted, he invited Paddock to Nevada to go fishing at Lake Mead and off-road biking in the desert.

Nixon said there were never any problems with their relationship, but later Paddock became "bitter at the system" and started "talking a lot about death." Paddock mentioned "going postal," which made Nixon concerned about Paddock's well-being, Nixon told CNN.

Nixon asked in a letter from August 2014 about a statement Paddock allegedly made about executing an upcoming plan, the Review-Journal said.

"You said in (3) years you would be ready and that your plan would show up in Nevada, California, Illinois, Texas, New York and other cities," the Review-Journal reported one letter said. "What do you mean?"

In another letter dated March 2, 2017, Nixon wrote: "You must going [sic] on a hunting trip with all those guns you are stockpiling," according to the newspaper.

"You are a good person and I want you to know that I am concern [sic] about you and your wellbeing," Nixon wrote in the letter dated May 27, 2017, the Review-Journal reported. "I believe you are lying to me and you are going to hurt someone or kill someone. You sound like a real mad man on the phone tonight."

Nixon told CNN that he never conveyed his concerns about Paddock to authorities because "he didn't know [Paddock] was going to do anything" and "couldn't read [Paddock's] mind."

Nixon said he didn't believe Paddock did it when the first reports identifying the suspect surfaced. But when authorities was confirmed it was Paddock, he said he thought, "Damn, that fool."

FBI has yet to confirm a motive for the massacre

About 22,000 people were attending a country music festival across the street from the Mandalay Bay on October 1, 2017, when Paddock opened fire. Witnesses said the gunfire last 10 to 15 minutes. Paddock, 64, took his own life before law enforcement officers knocked down his door, officials said.

Authorities at the time said they found 23 guns in the room, and 24 more at his two homes.

Investigators have for years searched for a motive. Recently, the FBI released a trove of documents that indicate he may have harbored resentment over how casinos treated him and other high rollers.

The heavily redacted documents -- which include hundreds of pages of investigation records, evidence inventories and interviews with people who knew Paddock -- also provide a fuller picture of the gunman's obsessive gambling habits.

Still, the investigative documents never arrive at a definitive motive.

The FBI opened its investigation the day after the massacre at the Route 91 Harvest music festival and closed it more than a year later, announcing it had found no clear motive for Paddock's attack.

Though the FBI said in 2019 that Paddock's actions were not driven by a grievance against any particular casino or hotel, one fellow gambler interviewed by investigators after the attack said Paddock had become angry about how casinos generally dealt with VIP players.

The gambler, whose name is redacted, told the FBI that Paddock was "upset at the way casinos were treating him and other high rollers" and that he believed the frustration could have caused the gunman to "snap," according to the documents.

The gambler said that while casinos typically treated high rollers to perks like free cruises and flights, he believed the venues' approach to such players had changed in the years leading up to the shooting, including banning them from some hotels or casinos, the documents said.

Paddock had been banned from three casinos he frequented in Reno, Nevada, the gambler said.

The gambler also believed the Mandalay Bay "was not treating Paddock well because a player of his status should have been in a higher floor in a penthouse suite."

Due to the redactions, it is unclear how the gambler knew Paddock.

Gunman was a 'prolific video poker player'

In order to become the priority player he believed he was, Paddock had spent -- and lost -- exorbitant amounts of money at casinos, according to people interviewed by the FBI.

The fellow gambler told investigators that Paddock had a bankroll of about $2 million to $3 million, the documents said.

He would regularly play for six to eight hours a day at casinos, and sometimes as many as 18 hours a day, the gambler said.

Investigators also spoke with a woman who worked at the Tropicana Las Vegas casino and resort -- just down the Strip from the Mandalay Bay -- who said Paddock would visit about every three months, according to the documents.

She described Paddock as a "prolific video poker player" who would only want to discuss gambling when they talked, the documents said.

During a three-day stay at the casino in September 2017, Paddock lost $38,000, she told the FBI.

Real estate agents told CNN in 2017 that Paddock said his income came from gambling and that he gambled about $1 million a year. He paid $369,022 in cash for the home they sold him in 2014, the agents said.