A 2019 report published by the Washington House of Representatives accused Shea of domestic terrorism in relation to his role in a series of standoffs with federal authorities.

[1][2] In October 2018, Shea acknowledged that he had distributed a four-page manifesto which called for the killing of non-Christian males if a war were to occur and they do not agree to follow fundamentalist biblical law.

[6] An investigative report commissioned by the House, issued on December 1, 2019, found that Shea "participated in an act of domestic terrorism against the United States", organized and supported "three armed conflicts of political violence", and advocated replacing the government with a theocracy and "the killing of all males who do not agree.

[22] During the 2016 occupation of the Malheur National Wildlife Refuge, Shea and other COWS members traveled to Burns, Oregon, allegedly attempting to negotiate on behalf of the militants occupying the reserve.

[23] In 2015, Shea supported Idaho Representative Heather Scott, a fellow COWS member, in a protest near the home of John Arnold.

[37] Shea has often clashed with journalists, referring to reporters as "dirty, godless, hateful people" at an August 2018 gun-rights rally.

[38] In late October 2018, Shea acknowledged that he had distributed a document described as a "four-page manifesto" titled Biblical Basis for War that listed strategies that a "Holy Army" could employ.

The document, consisting of 14 sections divided into bullet points, had a section on "rules of war" that stated "make an offer of peace before declaring war", which within stated that the enemy must "surrender on terms" of no abortions, no same-sex marriage, no communism and "must obey Biblical law", then continued: "If they do not yield — kill all males".

"[3][4][40] The Spokesman-Review reported: "After the document was leaked online Tuesday [10/23/18], the Spokane Valley Republican insisted he was not promoting violence and that the message had been taken out of context.

Other members in the chat group discussed carrying out surveillance, intimidation, and violent attacks on political enemies, including Antifa activists and "communists."

[42] The Guardian published a second set of emails in August that tied Shea to an organization called Team Rugged, which aimed to train young men for "biblical warfare".

[43][44] An investigation commissioned by Washington House of Representatives reported, on December 1, 2019, that Shea had planned and participated in domestic terrorism on at least three occasions.

"[47] The sheriff also stated that he was worried that arresting Shea would lead to an armed standoff, and that he had contacted the Federal Bureau of Investigation regarding this concern.

[47][46] Shea issued a statement to local news station KREM saying he had "been denied any opportunity to review and respond to its results which are still unknown to me.

"[48] That day, he wrote in a Facebook post: "Like we are seeing with our President this is a sham investigation meant to silence those of us who stand up against attempts to disarm and destroy our great country.

[51] In May 2020, Shea was fined $4,761.34 for damaging historic masonry by intentionally leaving a trail of slick olive oil on the steps of the Capitol.

[52] According to the leader of The Satanic Temple Lucien Greaves, "If Mr. Shea is so offended by our First Amendment guarantees that he finds it impossible to accept public religious expression that does not align with his own, then I hope the people of Washington will demand his immediate resignation."

"[53] At an event in North Idaho less than a month after the 2021 storming of the United States Capitol, Shea called for his followers to prepare for "total war" against their enemies, claimed the election was stolen from Donald Trump, and engaged in Islamophobic rhetoric, saying that during the Battle of Tours in 732, "The Army of Islam would go into churches and rape all the nuns on the altar until there were no more virgins left and then they'd start in on the boys.

[19] Shea denied any physical abuse, called his ex-wife a "product of the foster care system", and said this was her third divorce.