The man, Wesley Brian Kaster, was arrested Saturday, about three weeks after the authorities began investigating what they called a suspicious fire at the clinic on Feb. 10.

Don Ledford, a spokesman for the U.S. attorney’s office, declined to elaborate on a possible motive. “It’s early in the case,” he said. “It’s still an ongoing investigation.”

In court papers, prosecutors noted that Kaster’s wife had posted a picture on Facebook in 2015 showing a handgun and the caption, “Guns Don’t Kill People, Planned Parenthood Kills People.”

Kaster, who is in federal custody, faces one count of maliciously damaging a building owned by an organization that receives federal financial assistance, by means of fire or an explosive.

A phone call to a number listed for Kaster and his wife was not returned Monday. Troy Stabenow, a lawyer appointed Monday to represent Kaster, said he was still reviewing the complaint and declined to make a statement.

Planned Parenthood Great Plains, which oversees the clinic, the Columbia Health Center, said that it had reopened on Feb. 18.

“We are grateful for law enforcement’s swift and serious response to this crime,” Dr. Brandon J. Hill, the president and chief executive of Planned Parenthood Great Plains, said in a statement Monday.

The fire has drawn national attention at a challenging time for Planned Parenthood. Last month, the Trump administration announced it would bar organizations that provide abortion referrals from receiving federal family planning money, a move that could strip millions of dollars from the organization. On Monday, California filed suit to block the Trump administration’s move.

The Columbia clinic had been one of two places in the state offering abortion services. But it was forced to stop last fall when its sole doctor was unable to comply with new restrictions in Missouri that require abortion providers to obtain admitting privileges at nearby hospitals.

“The circumstances surrounding the fire are coming into focus, and it is clear that this was an intentional effort to damage our facility in order to disrupt services and block patient access to sexual and reproductive health care,” Hill said in a statement last month.

The FBI had said last month it was investigating possible civil rights violations in the case under the Freedom of Access to Clinic Entrances Act. “We would not rule that out,” Ledford said Monday.

Nobody was hurt in the fire, which was fully extinguished by a sprinkler system when firefighters arrived, according to court papers. The building was unoccupied at the time. Security footage showed someone wearing a hood leaving the area in the early morning hours as smoke rose from the clinic.

In court records, the authorities laid out parts of the investigation that led to Kaster’s arrest.

At the scene, investigators found 5-gallon buckets that had held gasoline, which they said was used to fuel the fire. They cross-referenced recent purchases of those buckets at a local hardware store.

Security footage captured a two-toned Toyota Sienna minivan missing a hubcap, so investigators pulled records for 55 such minivans registered to residents of Columbia, where Kaster lives.

They said their investigation found that Kaster had bought buckets on Feb. 8, and that a minivan registered to Kaster matched what was at the scene, among other evidence.

Investigators also found gloves at the scene. They contacted Kaster’s employer, a manufacturing company, which said it had issued the same type of gloves in January.

The authorities said, based on security footage, that Kaster broke the front door of the clinic and threw a “Molotov cocktail-type incendiary device” inside it.

No fire was visible, and he left as two unidentified people walked near the clinic. More than one hour later, he came back and walked to the clinic’s door. Shortly after, smoke came out of the broken front door and Kaster fled, the authorities said.

Kaster is due in court Thursday.

This article originally appeared in The New York Times.