Mourners gather at a candle-filled memorial for slain artist and activist Alicia Cardenas, the owner of Sol Tribe Custom Tattoo and Body Piercing, who was killed in a shooting spree that left five victims dead the previous night, as on Tuesday, Dec. 28, 2021, at Sol Tribe Custom Tattoo in Denver, Colo. (Timothy Hurst/The Gazette)

The man who killed five people in a shooting rampage Dec. 27 cut all ties with friends and sold his possessions, was trying to recruit people who follow him into a war on American soil, bragged about having flamethrowers and other weapons, and wanted to take down an apartment building.

This is all according to internal documents from the Denver Police obtained by The Denver Gazette, which outline a letter of warning sent to them by a man in Germany who had been following McLeod's movements at the end of 2020.

Police records revealed that law enforcement received an eight-page letter from a whistleblower in Germany a little over a year to the day that Lyndon McLeod went on attack in Denver and Lakewood.

Andre Thiele of Wolfsburg, Germany, detailed why he was alarmed by some of McLeod's writings in his Sanction Tribe channel on the messaging platform Telegram from Nov. to Dec. 2020. Among McLeod's posts were "War is coming," "Pain demands a response," "But those consequences are coming. 3...2..." and "God, the great mathemetician, wants endless-if punctuated-war. And all this hippy peace and forgiveness talk is wicked in my opinion."

“Though the book is not political per se, it could be read as a extremist right-wing manifesto and a terrorist prophecy,” Thiele wrote.

“He has a motive, he has the means, and he has put a target date on his ‘project’, which makes it a sick, but effective plan.”

Thiele told The Denver Gazette he hoped for law enforcement to look closely at what he had discovered and come to an educated decision about what to make of it. He said he is disappointed Denver police didn’t take more action, but doesn’t have animosity toward the department about it.

“I knew that the facts I could provide were thin and circumstantial and that my prediction at that point in time was nothing but a hunch. Yes, I am disappointed, that Denver PD did not take action - but I understand that what I offered just wasn‘t enough,” he said.

“I have no hard feelings towards DPD. Hopefully one day we will have better ways of spotting potential killers - but we are not there yet.”

Thiele prefaced his letter to Denver police saying that there was a 90% chance that McLeod was just a “petty thug, who talks too much,” but that there was a 10% chance McLeod had "created the perfect storm of right-wing terrorism."

Police said in a statement to The Denver Gazette they did not find sufficient evidence for criminal charges or a legal basis for monitoring McLeod at the time. But the department is reviewing its investigation, police confirmed.

“DPD is reviewing the January 2021 investigation as part of our overall investigation into the homicide/shooting incidents in Denver, so we are unable to provide additional comment on the tip or investigative process at this time.”

Thiele described McLeod’s followers as a “tribe.”

Also included the police documents were the interactions they'd had with McLeod when he lived in Denver, including a May 2015 domestic violence incident and two traffic accidents. For one, he received a citation for careless driving in June 2015.

He sued Valerie Degroot in 2014 over a crash in November 2012 on North Bryant Street in Denver. She told The Denver Gazette she was a teenager at the time, and had just gotten her driver’s license. Degroot said the accident was her fault and McLeod was angry and yelling at the scene of the crash, but otherwise seemed like he had not been seriously hurt.

He claimed in the lawsuit he suffered injuries and lost work because of the crash, but Degroot said he dropped the case when he was pressed to produce evidence and realized her father had money to fight the litigation.

“I just kind of thought he was a creep who was trying to take advantage of the mistake I made,” she said, adding she remembers “thinking it was really weird that [McLeod] was trying to sue” a teenager.

Thiele wrote the Denver police that McLeod was target practicing with assault weapons, stealing money from people he was living with in Memphis, Tenn., and was attempting to have relationships with underaged girls, specifically by using a single mother he was dating who had a young daughter.

The gunman's million-page book trilogy, Sanction, also worried Thiele, who warned police that it was a terrorist manifesto McLeod was using to start a war.

“Collapse MUST COME [sic] regardless of the details. All politics is pointless and to even think it matters who is president (or what policies are enacted) is to miss the point. War is coming just as forest fires come,” he wrote in Telegram, according to an excerpt from police documents.

McLeod published his books under a pseudonym, Roman McClay, but uses a title character that shares his name. Denver Gazette news partner 9News previously reported one of the books describes the title character killing a man named Michael Swinyard in an apartment building on Williams Street by Cheesman Park.

A 67-year-old man named Michael Swinyard was among the rampage’s victims, and he was killed at an apartment building on Williams Street bordering the park.

Another book included a passage about the main character walking into a tattoo shop on Sixth Avenue in Denver and killing a woman, according to the TV station. Police say McLeod killed Alicia Cardenas and Alyssa Gunn-Maldonado at the Sol Tribe tattoo shop on Broadway, which Cardenas owned.

Amazon removed the books the same week as the shooting rampage.

Thiele’s letter to police lists four Twitter accounts allegedly linked to McLeod. The names on two of them use the Roman McClay pseudonym. The two accounts still active have not tweeted since 2020.

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