Originally Published: 28 OCT 22 08:43 ET

Updated: 28 OCT 22 12:15 ET

By Whitney Wild, John Miller, Clare Foran and Jamie Gangel, CNN

(CNN) -- Paul Pelosi, the husband of House Speaker Nancy Pelosi, was attacked with a hammer at the couple's home in San Francisco by a male assailant early Friday morning, law enforcement sources tell CNN.

The assailant who attacked Paul Pelosi was searching for the speaker of the House, according to a source briefed on the attack. The intruder confronted the speaker's husband in their San Francisco home shouting "Where is Nancy, where is Nancy?" according to the source.

Pelosi, 82, was hospitalized but is expected to make a full recovery, the Democratic speaker's office said in a statement.

The US Capitol Police released a statement saying that they are assisting the FBI and the San Francisco Police "with a joint investigation" into the break-in at the Pelosi residence in California.

The statement provides further information on how law enforcement responded, saying that special agents with the USCP's California Field Office "quickly arrived on scene, while a team of investigators from the Department's Threat Assessment Section was simultaneously dispatched from the East Coast to assist the FBI and the San Francisco Police with a joint investigation."

Drew Hammill, a spokesman for Nancy Pelosi, said the assailant is in custody and a motive is being investigated. The speaker was in Washington at the time of the attack, a spokesperson said.

"The Speaker and her family are grateful to the first responders and medical professionals involved, and request privacy at this time," Hammill said in his statement.

The assailant entered the Pelosi residence through the back of the house, according two sources familiar with the early details of the incident.

With Speaker Pelosi away, there would not have been a security detail at the residence, according to one source familiar with protocol.

There may be video that US Capitol Police and law enforcement can review as there are security cameras at the home, according to two law enforcement sources.

President Joe Biden spoke with Speaker Pelosi, the White House said.

"The President is praying for Paul Pelosi and for Speaker Pelosi's whole family. This morning he called Speaker Pelosi to express his support after this horrible attack," press secretary Karine Jean-Pierre said in a statement.

She continued: "He is also very glad that a full recovery is expected. The President continues to condemn all violence, and asks that the family's desire for privacy be respected."

Senate GOP Leader Mitch McConnell said in a tweet on Friday he is "horrified and disgusted" by the reports that Pelosi was assaulted in his home.

"Grateful to hear that Paul is on track to make a full recovery and that law enforcement including our stellar Capitol Police are on the case," the Kentucky Republican said.

The Pelosis have been married since 1963 and have five children.

This story and headline have been updated with additional developments.