The story was shocking from the beginning. Someone had broken into the San Francisco home of House Speaker Nancy Pelosi and swung a hammer at her 82-year-old husband, Paul Pelosi, fracturing his skull.

But in the past week, city and federal investigators have released an array of details that paint an ever-darkening picture of the middle-of-the-night attack, in which a man obsessed with far-right conspiracy theories allegedly tried to kidnap the Democrat who increasingly stars as the villain in those fantasies.

The alleged intruder, 42-year-old David Wayne DePape, now faces charges in both state and federal courts. He has pleaded not guilty to the local charges, and his public defender has suggested he may have been vulnerable to disinformation. Paul Pelosi needed surgery but has been released from the hospital and is expected to recover.

The case has raised alarm among Democrats, who see a direct line between far-right rhetoric and such violence. Meanwhile, some Republican leaders, including former President Donald Trump, have responded by promoting additional conspiracy theories about what happened in the Pelosis’ home.

The following account of what unfolded in about half an hour on Oct. 28 is based on court filings by the San Francisco District Attorney’s Office, the FBI and the U.S. Attorney’s Office; statements by Police Chief Bill Scott; interviews by Chronicle reporters; and a review of documents, videos and photographs.

A figure in black

Shortly after 2 a.m. Friday, a private security guard who was parked near the Pelosis’ stately, three-story brick home on a corner lot in Pacific Heights noticed a man in black clothing walking outside of it.

Inside the home, Paul Pelosi was alone, sleeping in an upstairs bedroom in a pajama shirt and boxers. His wife — second in succession to the presidency — was in Washington, D.C.

The guard, who was working for a neighbor in an area with an array of multimillionaires and billionaires, said the man on the street, who police now say was DePape, wore black and carried a large backpack. It’s not clear how DePape got there from Richmond across the bay, where he had rented the garage of a small home, but investigators said they found Clipper transit cards in the right front pocket of his shorts.

A native of Canada who was once registered with the Green Party, and who was in a long relationship with a woman who fought public-nudity laws, DePape had struggled with mental illness, according to people who knew him. More and more, he had become consumed with far-right politics and conspiracy theories, and he posted bigoted rants on personal websites that appeared to have no audience.

Soon, the guard in the neighborhood — who has not been identified — heard a loud bang, but apparently did not call 911, according to records. The sound, investigators believe, was DePape using a hammer to bash through a glass rear entryway to the Pelosi home. A video shot by a KGO-TV helicopter shows a gaping hole in glass near a doorknob.

Official accounts say nothing about whether the Pelosis had an alarm system. But the break-in was captured on a camera feeding live video to the command center for the U.S. Capitol Police, the Washington Post reported. The newspaper said no one was watching the feed in real time, though.

The breaking of glass did not awaken Paul Pelosi.

Awakened to an intruder

It wasn’t until the intruder was standing over Paul Pelosi’s bedside that he was startled awake. City prosecutors, in a court filing asking a judge to hold DePape without bail, gave the following account of the men’s conversation:

“Are you Paul Pelosi?” DePape asked, gripping a large hammer in his right hand and white plastic zip ties in his left. “Where’s Nancy? Where’s Nancy?”

“She’s not here,” Paul Pelosi responded.

“Well, when is she going to be back?”

“She’s in Washington,” Pelosi said. “She’s not going to be back for a couple of days.”

“OK,” DePape said. “Well, I’m going to tie you up.”

Pelosi recalled later that he stood up and tried to escape, trying to bolt into the home’s elevator off the bedroom. DePape allegedly used an arm to hold the door. Pelosi then walked back into the bedroom, sat down on the bed and asked DePape why he wanted to see his wife.

“Well, she’s No. 2 in line for the presidency, right?” DePape reportedly said, to which Pelosi agreed. DePape explained that they were “all” corrupt, and that “we’ve got to take them all out.”

Pelosi asked DePape if he could call anyone for him. DePape, prosecutors said, responded that this was the “end of the road” for Pelosi.

A strange 911 call

Fearing what the intruder would do, Paul Pelosi soon asked if he could go to the bathroom.

DePape agreed, investigators said, allowing Pelosi access to his phone — which was charging in an outlet in the bathroom. Pelosi grabbed the phone, turned it on and called 911 on speaker. DePape stood about 3 feet away, still holding his hammer and zip ties.

A mile and half away, at the city’s emergency operations center on Turk Street, dispatcher Heather Grives answered the call at 2:23 a.m., according to a court affidavit by FBI Special Agent Stephanie Minor. Officials have said Pelosi kept the line open and, with the intruder nearby, spoke in a sort of code.

“Mr. Pelosi said that there was a gentleman there waiting for his wife (Nancy Pelosi) to come back,” city prosecutors wrote. “But Mr. Pelosi said they would have to wait because his wife would not be coming back for about a day.”

In what prosecutors described as an attempt to defuse the situation, Paul Pelosi told the dispatcher he didn’t need police, fire or medical assistance. Yet he continued to speak in coded language, attempting to relay the urgency of the situation to authorities without upsetting the stranger in his home.

Pelosi asked the dispatcher for Capitol police, saying they were typically the ones at the house protecting his wife. Grives responded with a clarification, reminding Pelosi he was calling San Francisco police.

Pelosi told Grives he understood, then asked out loud, “I don’t know, what do you think?” Grives heard another male voice answer: “Everything’s good,” prompting Pelosi to say, “Uh, he thinks everything’s good. … Uh, I’ve got a problem, but he thinks everything’s good.”

When Grives told Pelosi to call back if he changed his mind, Pelosi grew more urgent. “No, no, no,” he said, “this gentleman just uh, came into the house uh, and he wants to wait for my wife to come home.”

Grives asked Pelosi if he knew the man, and Pelosi said he didn’t. The man, Pelosi told Grives, was telling him not to do anything. Grives asked for Pelosi’s name and address and Pelosi gave both. When Grives asked what the man’s name was, it was DePape who responded: “My name is David.”

Grives then asked who David was, prompting conflicting responses. “I don’t know,” Pelosi said. “I’m a friend of theirs,” DePape countered.

Pelosi reiterated that he didn’t know the man.

“He’s telling me I am being very lazy, so I’ve gotta stop talking to you, OK?” Pelosi said.

Grives offered to stay on the line to make sure everything was OK. “No, he wants me to get the hell off the phone,” Pelosi said — and the call ended.

At 2:27 a.m., Grives issued a high-priority “well-being check” for police to visit the Pelosi home.

Chief Scott said Grives was suspicious enough about what she heard from Paul Pelosi that she boosted the priority from a “well-being check” to a Code 3 emergency. “She just knew there was more to it,” Scott said.

After the call, DePape told Pelosi he had tired himself out carrying his backpack to the residence and needed to sleep, according to Minor, the FBI agent. The two descended the stairs, with DePape following Pelosi with the zip ties and hammer.

DePape worried aloud that the police would be there any minute, and Pelosi attempted to keep him calm by assuring him they wouldn’t. DePape was unconvinced.

“I can take you out,” he allegedly said, moving to Pelosi’s right and gripping the hammer upright. Fearing the intruder would strike, Pelosi put his hand on the hammer’s handle.

At 2:31 a.m., according to police officials, officers Kolby Wilmes and Kyle Cagney pulled up to the Pelosi home.

Tackled, but too late

Officers Wilmes and Cagney walked to the front of the home and rang the doorbell. Inside, investigators said, DePape ordered Pelosi not to open the door, but he did anyway, leading to a pivotal confrontation in a dimly lit foyer.

“As the door opened,” prosecutors wrote, “Mr. Pelosi nervously but calmly greeted them. When the officer asked what was going on, Defendant smiled and said, ‘Everything’s good.’”

After an officer turned on his flashlight, DePape could be seen holding the bottom of the hammer with one hand and Pelosi’s right arm with the other. Pelosi gripped the same hammer, near the top of the handle.

“Drop the hammer!” one officer shouted.

“Um nope,” DePape responded, then pulled at the hammer, twisting one of Pelosi’s arms as the older man pleaded, “Hey, hey, hey!”

According to the district attorney’s account, an officer asked, “What is going on here?” as Pelosi lost his grip on the hammer. DePape stepped back and swung the tool, striking Pelosi in the head. He was unconscious as the officers rushed into the house, tackled DePape and took away the hammer.

“Mr. Pelosi remained unresponsive for about three minutes,” prosecutors wrote, “waking up in a pool of his own blood.”

‘A suicide mission’

DePape was still at the Pelosi home when he began talking, city prosecutors said.

“I’m sick of the insane f— level of lies coming out of Washington, D.C.,” DePape told officers and medics, though none had asked him questions. “I came here to have a little chat with his wife.”

“I didn’t really want to hurt him, but you know this was a suicide mission,” DePape continued. “I’m not going to stand here and do nothing even if it cost me my life. Hurting him was not my goal. I told him before I attacked him, that he’s escalating things, and I will go through him if I have to.”

According to prosecutors, DePape went on to make a full confession.

He reportedly told investigators he intended to take Nancy Pelosi hostage and talk to her. If she told the truth, DePape said, he would let her go. If she lied, he would break her kneecaps. And DePape said he didn’t expect Pelosi to tell the truth.

With the speaker’s kneecaps broken, DePape explained, “she would then have to be wheeled into Congress, which would show other members of Congress there were consequences to actions,” the FBI said in a court filing. “DePape also explained generally that he wanted to use Nancy to lure another individual to DePape.”

When investigators asked if DePape had other plans, he said he did, that his targets included a local professor and other prominent state and national politicians, as well as their spouses.

Throughout the interview, DePape indicated he was undeterred by the prospect of being caught.

“DePape explained,” federal prosecutors wrote, “that he did not leave after Pelosi’s call to 911 because, much like the American founding fathers with the British, he was fighting against tyranny without the option of surrender.”

Megan Cassidy is a San Francisco Chronicle staff writer. Email: megan.cassidy@sfchronicle.com Twitter: @meganrcassidy