Holden Matthews faces charges of three counts of simple arson on religious buildings. If convicted he could be sentenced to up to 15 years in prison per charge, State Fire Marshal Butch Browning said at a news conference.
Authorities said they are working to determine if racial bias was a motivation in the alleged crimes, and if the suspect was influenced by a subgenre of music linked to white nationalist ideology.
Matthew's father, Roy Matthews, is a St. Landry Parish sheriff's deputy, and was unaware of his son's alleged involvement and was not personally part of the investigation, Sheriff Bobby Guidroz told reporters. All three churches that were burned were in St. Landry Parish, north of Lafayette.
"That's tough," Guidroz said after Roy Matthews learned of his son's alleged connection. "That tells you, and it should tell the country, no matter who you are, there are consequences."
Holden Matthews, who was taken into custody late Wednesday without incident, has a possible connection with "black metal" music and "its associated history with church burnings in other parts of the world," the fire marshal said.
"This is an attack on the house of God," he said.
On a Facebook page that appears to belong to Matthews, he is listed as the lead singer of a band called Vodka Vultures and is pictured in front of graffiti that says "black metal."
Officials said that Matthews didn't have a criminal history, but they had arrested him in an effort to avert "what could have been other crimes."
The Morning Rundown
Get a head start on the morning's top stories.
An investigator said in an affidavit filed in the case that a charred gas can was found near the origin of one of the fires and that the same type of gas can, as well as automotive shop towels and a lighter, were purchased at a Walmart late on March 25 less than three hours before the first church fire was reported.
Matthews was driving a pickup truck, and surveillance video from one of the fires showed a truck of that type, according to the affidavit. In addition, cellphone tower data revealed GPS coordinates put a device with a cellphone number known to belong to Matthews in the surrounding area of all three fires, the affidavit said.
An attorney whom a court clerk said was listed as representing Matthews did not immediately return a phone message Thursday.
FBI agents said that the agency still needed to "gather all the facts" to determine if the blazes were a "bias-related event."
About 200 people, including from the FBI and the Bureau of Alcohol, Tobacco, Firearms and Explosives, were on the case. The three churches were historically black and more than 100 years old, according to the NAACP branch in Lafayette.
The first fire was reported March 26 at St. Mary Baptist Church in Port Barre; the second on April 2 at the Greater Union Baptist Church in Opelousas; and the third last Thursday at Mount Pleasant Baptist Church, also in Opelousas.
The churches were empty at the time of the fires, officials said, and each suffered considerable damage, forcing worshippers to hold Sunday services at other locations. (A fourth fire last weekend at a church with a predominantly white congregation in another parish 200 miles away doesn't appear to be connected, authorities said Thursday.)
St. Landry Parish, with a population of more than 83,000, is about 56 percent white and 42 percent black, census data shows. Guidroz said police in the parish worked with pastors at other black churches to step up safety patrols.
The fires have been unnerving for churchgoers in the region because they conjure up images of attacks on black churches in the South during the civil rights movement, and more recently, during the 1990s.
"It has been especially painful because it reminds us of a very dark past of intimidation and fear," Louisiana Gov. John Bel Edwards said at Thursday's news conference.
Keegan Hankes, a senior research analyst at the Southern Poverty Law Center, which tracks hate groups, said white nationalists or neo-Nazi members have ties to bands that play black metal — itself categorized as a subgenre of heavy metal.
"Just to be clear, not all black metal has to do with far-right politics, and a lot of people outwardly reject (black metal musician Varg Vikernes) for his far-right politics," Hankes said.
Vikernes, who had been a member of the Norwegian band Mayhem, was convicted in the 1990s of manslaughter in the stabbing death of a fellow bandmate and for arson attacks on three churches in Norway, The Associated Press reported. He was later paroled and living in France, where officials in 2013 dropped terror charges against him but still wanted to take him to court for alleged anti-Semitic and xenophobic messages.
The SPLC said Matthews appeared to comment on Facebook about a 2018 movie, "Lords of Chaos," based on Vikernes and his band. The movie drew debate about its accuracy. In the post, Matthews said he enjoyed the film.
Hankes said there was nothing associated with Matthews' account that immediately suggested he had any greater connection with Vikernes.
Dana Nichols, the special agent in charge with the ATF's New Orleans division, said Thursday that there is "zero tolerance" for these attacks, particularly on houses of worship.
"With today's arrest, I want to send a strong message to those individuals who wish to engage in this heinous senseless crime: The church is a sacred place and it is the foundation of our faith and what this country is built on," she said.
"You cannot destroy our faith. We can have church anywhere," Nichols said, adding, "We'll have church in the very parking lot of the building you destroyed."
Erik Ortiz is a staff writer for NBC News focusing on racial injustice and social inequality.
Phil Helsel is a reporter for NBC News.
Tom Junod, Carmen Gonzalez and Gabe Gutierrez contributed.