A North Texas militia member and vigilante who led armed patrols of the Texas-Mexico border and was wanted by federal authorities died of an apparent self-inflicted gunshot wound, according to law enforcement officials.

Kevin Lyndel Massey’s body was discovered Dec. 23 in Van Zandt County, according to the sheriff.

Pending autopsy results will officially determine the cause of death, Sheriff Dale Corbett said.

Massey, 53, went into hiding around May 2019, several months after being released from prison on probation for a federal weapons charge.

Officials had warned that his vows to wage war against the federal government made him a dangerous threat. Massey amassed a strong and loyal following on social media in which supporters praised him for taking a stand against federal authorities. They claimed he was a patriot who was being persecuted by tyrannical government authorities.

The family planned to hold a memorial service at 3 p.m. Friday at a funeral home in Greenville. Family members could not immediately be reached for comment. When reached by phone, Massey’s ex-wife said she had no comment. Massey’s former defense attorney said he did not know about Massey’s death.

Deputies with the Van Zandt County Sheriff’s Office responded to a 911 call at 6:40 p.m. Dec. 23 about an “unresponsive person” in Wills Point, according to a news release. The town has a population of about 3,500 and is less than an hour east of Dallas.

Kevin L. Massey (U.S. Marshals)

Deputies found Massey’s body in a “small wooded area.” Fingerprints confirmed his identity, the sheriff’s office said. The death remains under investigation by the sheriff’s office, the U.S. Marshals and the FBI.

The marshals have said that Massey, of Royce City, had most recently lived in Quinlan, east of Dallas. Federal authorities said Massey, who espoused anti-government rhetoric, had an affinity for heavy weaponry and was known to display an "alarming rage."

News of Massey’s death comes as a different border vigilante pleaded guilty to a federal weapons charge in New Mexico.

Larry Mitchell Hopkins, 69, was “commander” of United Constitutional Patriots, a militia group based in New Mexico that, like Massey’s group, also detained migrants at gunpoint along the U.S.-Mexico border. Hopkins was scheduled to plead guilty Friday to one count of being a felon in possession of a firearm. He faces up to 10 years in prison, according to court records.

The FBI said it visited Hopkins’ home in October 2017 after receiving reports of “militia extremist activity.” The militia had its “base” at Hopkins’ home, and members of the group were armed with AK-47s and other weapons, court records say. Hopkins, according to witnesses, said his militia was training to assassinate George Soros, Hillary Clinton and Barack Obama, according to federal court records.

A Border Patrol agent detains suspected unauthorized immigrants in the area of Walker Canyon in Arizona. (John Moore / Getty Images)

Massey, an electrician, was sentenced to 41 months in federal prison in 2016 for possession of a firearm by a felon, according to court records.

Law enforcement officials have warned about a rise in right-wing extremist activity in recent years that includes militia groups.

Although Massey called himself a patriot, the FBI considered him a domestic terrorist with “violent tendencies,” according to court records.

He was once found with 20 homemade explosive devices and other weapons and was considered armed and dangerous when he disappeared. His prison writings, archived online by a supporter, as well as his Facebook posts show that he fervently embraced right-wing extremist movements, all of which deny the legitimacy of the U.S. government and any laws limiting gun ownership.

"Defendant Massey is a man who calls upon God to end the lives of the innocent to gratify his anger," Assistant U.S. Attorney William Hagen wrote in 2015 in his unsuccessful attempt to seek a tougher prison term for Massey. "Defendant has called upon those who may share his misguided and misinformed views to take up arms in resistance against civilized laws enacted to protect the public."

Recent domestic attacks have involved young men with white supremacist views. Experts on extremism in the U.S. say militias are less lethal than white supremacist terrorists. But over the past 25 years, anti-government groups and white supremacists have been responsible for roughly the same number of terror plots and attacks, according to the Anti-Defamation League’s Center on Extremism.

Massey gained infamy in 2014 for his activities in Brownsville as a member of a border vigilante group called Rusty's Rangers.

Prosecutors said Massey, dressed in military fatigues, conducted armed patrols with others on the South Texas border in 2014 to search for immigrants attempting to cross into the U.S.

The militia members, displeased with U.S. border enforcement, said they took matters into their own hands after obtaining permission to access private property. Their makeshift "Camp Lonestar” on rural land served as a “staging area for their patrols,” according to a federal search warrant application.

Massey routinely videotaped his border activities and posted them on Facebook, court records say. He would later say on Facebook that he had the power of citizen’s arrest. In Facebook posts, Massey described detaining immigrants at gunpoint and binding their wrists with zip ties.

He vowed to remain at the border until regulators "sealed the border or there's some sort of civil war," federal authorities said.

Massey also has claimed in court documents to be a “sovereign man,” someone who is not a U.S. citizen and not under U.S. jurisdiction. A Facebook page created for him called Massey a “patriot who served on the Texas border repelling foreign invaders.”