David C. Joseph, the United States attorney for the Western District of Louisiana, confirmed in a statement that a suspect was in custody. He did not elaborate.
U.S. Rep. Clay Higgins said the suspect was the son of a St. Landry Parish deputy sheriff.
The fires, which destroyed the three churches, occurred March 26, April 2 and April 4 in St. Landry Parish, north of Lafayette. Officials had said they had found “suspicious elements” in each case.
A fourth fire, a small blaze that officials said was “intentionally set,” was reported March 31 at a predominantly white church in Caddo Parish, about a three-hour drive north. It was unclear if that fire was connected to the others.
Gov. John Bel Edwards of Louisiana and law enforcement officials were scheduled to provide details on the arrest at a news conference Thursday morning in Opelousas, Louisiana, in St. Landry Parish.
The FBI and the federal Bureau of Alcohol, Tobacco, Firearms and Explosives had been involved in the investigation, as well as the Louisiana and Florida state fire marshals, the cybercrime unit of the Louisiana Attorney General’s office, and state and local police.
Since the 1950s, black churches across the South have been the targets of racist attacks, from arson and bombing to armed assault.
This article originally appeared in The New York Times.