What We Know About the Arson Attack on Gov. Josh Shapiro’s House in Pennsylvania

Gov. Josh Shapiro of Pennsylvania and his family were forced to flee from the governor’s official residence early Sunday when an arson attack severely damaged the mansion.

The authorities arrested a man who they said had broken into the mansion in Harrisburg, Pa., and had thrown homemade incendiary devices that ignited fires into two rooms. No one was injured in the attack.

The man, who they identified as Cody Balmer, 38, has been charged with attempted murder, aggravated arson, terrorism and other offenses. Law enforcement officials have not provided any information about a motive.

Here is what to know about the attack.

Governor Shapiro and his family were sleeping when the fires were set.

Mr. Shapiro said that he, his wife and children were awakened shortly after 2 a.m. by a state trooper who warned them of a fire. They were rushed to safety while firefighters extinguished the flames, he said. The F.B.I. was assisting in the investigation, he added.

Mr. Shapiro, a Democrat, rose to prominence last year when he was on the short list of possible running mates for Kamala Harris, the party’s nominee for president. He helped oversee the law enforcement response to the assassination attempt against Donald J. Trump in Butler, Pa., who was then campaigning for president.

The 51-year-old governor, who has said that there was too much vitriol in American politics, noted that the attack on the residence occurred shortly after his family and others members of the local Jewish community had celebrated the first night of Passover in the state dining room, one of the rooms that was set ablaze in the attack.

The suspect admitted starting the fires, officials said.

The authorities said surveillance footage showed a person checking out the governor’s mansion before scaling a fence and using a hammer to break a window on the south side of the residence. He threw an object into the house, igniting a fire, the Dauphin County District Attorney said in a statement.

He then broke into the building through a window on the east side and threw at least one more object, starting another fire, before fleeing, the district attorney said.

When the state police became aware of a security breach on the property, they started looking for an intruder, officials said. But Mr. Balmer had broken in, set the fires and escaped again within a few minutes, and was not caught at the scene, they said.

According to an affidavit filed with the criminal complaint early on Monday, a woman contacted the police on Sunday to tell them that Mr. Balmer, her ex-partner, had confessed to her that he had committed the attack. He later turned himself in at state police headquarters in Harrisburg, where he was arrested, the affidavit said.

Officials said at the news conference on Sunday and in the affidavit that Mr. Balmer admitted to state troopers that he had set the fires.

The charges include attempted murder and terrorism.

The police’s criminal complaint accuses Mr. Ballmer of attempted murder, aggravated arson, burglary, reckless endangerment, terrorism, aggravated assault and related offenses.

When state troopers questioned him and asked what he would have done if Mr. Shapiro had found him, Mr. Balmer said that he would have beaten the governor with his hammer, the police affidavit said.

In a statement on Monday, the state police said Mr. Balmer had been taken to a hospital and was receiving treatment there “due to a medical event not connected to this incident or his arrest.” He will be arraigned once he is released from the hospital, the statement said.

The governor’s residence suffered significant damage.

The fires caused significant damage to parts of the residence, particularly the dining and piano rooms, the authorities said.

Photos released by the authorities showed singed walls, broken windows and blackened floors.

The governor’s residence is a 29,000-square-foot Georgian-style building on the Susquehanna River that was completed in 1968, according to the state government. Its landscaped grounds occupy a full block about a mile and a half from the State Capitol complex. The police said Mr. Balmer gained entry and fled the grounds on the southern side, where there is an office building and a parking lot across a narrow side street from the perimeter fence.

The public is able to tour the residence, which exhibits art and artifacts on the first floor.