The suspect in arson fires that destroyed three black churches in rural Louisiana was “active” on Facebook pages popular with neo-Nazis, state and local officials said Thursday.

Holden Matthews, 21, was arrested Wednesday on three counts of arson for the fires in March and April in rural St. Landry Parish. Matthews is the son of a sheriff’s deputy.

At a news conference, Louisiana Gov. Bel Edwards (D) branded the fires an “evil act,” adding that the experience “has been especially painful because it reminds us of a very dark past of intimidation and fear.”

“During Reconstruction and the civil rights movement, black churches were targeted with fires, bombings and threats,” notes the Washington Post.

Rep. Clay Higgins (R-LA) called the fires an “affront against God himself and his children.”

An FBI agent at the news conference said an investigation will determine if the attacks were federal hate crimes, which would mean far more serious charges against Matthews.

“A Facebook page that appeared to belong to Matthews showed he was active in pagan and black metal pages,” says the Daily Beast, “and that he commented on … [a] far-right former neo-Nazi metal musician” in Norway who murdered a fellow musician and burned churches.

State Fire Marshal H. “Butch” Browning said that once authorities identified Matthews as a suspect, they “raced to arrest him,” because they “felt other crimes were imminent,’ the Post reports.

St. Landry Parish Sheriff Bobby Guidroz said Matthews’ father, Deputy Roy Matthews, aided in the arrest by directing his son away from home.

The Daily Beast quotes the pastor of the Mount Pleasant Baptist Church — one of the burned churches — as saying, “We’ve suffered, but I think it has a higher cause.”

“Even though we’ve lost our church—our building, our building—look who’s been brought together,” said Pastor Gerald Toussaint. “Our country has to find out that the God we serve does not look on the outside. He sees the heart.”

Earlier this week, NAACP president Derrick Johnson called the fires “domestic terrorism.”