Paul Pelosi
Paul PelosiStefano Costantino / SOPA Images via Reuters Connect

Federal authorities on Monday charged California man David DePape with attempting to kidnap US House Speaker Nancy Pelosi last week when he broke into her San Francisco home and attacked her husband Paul, AFP reports.

The Justice Department said DePape had tape, rope, zip ties and other materials with him indicating he had intended to tie up Pelosi when he broke into her home on Friday, but found only her husband, whom he attacked with a hammer.

In a court affidavit, the FBI said DePape told them after his arrest he viewed Nancy Pelosi as responsible for lies told by her Democratic Party.

The affidavit said DePape intended to hold Pelosi, who is second in line to the US presidency after the vice president, hostage and talk to her.

"If Nancy were to tell DePape the 'truth,' he would let her go, and if she 'lied,' he was going to break 'her kneecaps,'" the affidavit said.

DePape, 42, who lived in a garage in nearby Richmond, California and had posted right-wing conspiracy theories on social media, broke into the house early Friday when only Paul Pelosi was there.

Pelosi called 911 when he encountered the threatening man and left the line open so a dispatcher could hear his conversation with DePape, speaking surreptitiously but making it clear that he needed help, according to a law enforcement source.

San Francisco police entered the home around 2:27 a.m. local time to find Pelosi struggling over a hammer with a man, who has since been identified as DePape, according to the city’s police chief.

Officers saw DePape “violently assault” Pelosi with the hammer before they tackled him to the ground and arrested him.

Pelosi was taken to a hospital after the attack and underwent surgery to repair a skull fracture and serious injuries to his right arm and hands and is expected to make a full recovery.

DePape later told authorities that Paul Pelosi was "taking the punishment instead" of his wife, given her absence., according to AFP.

DePape has been charged with one count of attempted kidnapping of a US official in relation to her official duties, and one count of assault of a US official's family member in retaliation for the official's actions.

The kidnapping charge brings up to 20 years in prison and the assault charge a maximum of 30 years in prison.

The US House Speaker on Saturday night spoke out about the attack on her husband, writing in a letter to all members of Congress that her family is "heartbroken".

"Yesterday morning, a violent man broke into our family home, demanded to confront me and brutally attacked my husband Paul. Our children, our grandchildren and I are heartbroken and traumatized by the life-threatening attack on our Pop. We are grateful for the quick response of law enforcement and emergency services, and for the life-saving medical care he is receiving," Nancy Pelosi said in the "Dear Colleague" letter to all members of Congress on Saturday.