But the police found the biggest cache of Durst materials concerning his enigmatic life in the cellar of a friend’s house 60 miles north of New York City, in the Hudson Valley, a rural spot Mr. Durst visited occasionally when he wanted some serenity.
The authorities believed that Mr. Durst, who is from a New York real estate family and has been a longtime suspect in several murders, was preparing to flee when they arrested him in the shooting death of his friend and confidante, Susan Berman, in Los Angeles in 2000. Mr. Durst is also a suspect in the disappearance of his first wife, Kathleen Durst, in 1982.
Only hours before the conclusion of an HBO documentary about Mr. Durst and the murders last Sunday, a State Police investigator, Joseph Becerra, arrived at the home of Susan T. Giordano in Campbell Hall, N.Y., to seize a trove of Mr. Durst’s private papers stored there.
Ms. Giordano said Mr. Becerra told her that she could release the material to him or he would obtain a search warrant and return. Ms. Giordano said she decided to let him have the documents.
The authorities ultimately hauled away about 60 file boxes, Ms. Giordano said, including phone records, bills, family-trust documents, photographs, video depositions from a lawsuit he filed against his brother and transcripts from his 2003 murder trial in Texas, where he was found not guilty of murdering his neighbor.
Ms. Giordano defended Mr. Durst against the latest charge.
“He didn’t do this,” said Ms. Giordano, who first met Mr. Durst through mutual friends about 30 years ago. “I’m such a strong believer in him. There’s probably some explanation. I don’t know what it is. I’m still waiting to hear from him.”
Mr. Becerra, who declined to comment, has a history with Mr. Durst. Acting on a tip, he dusted off old records in 1999, interviewed witnesses again and reopened an investigation into the disappearance of Mr. Durst’s wife. That case is still open.
Mr. Durst’s respite at Ms. Giordano’s home provides a glimpse into his complicated life. In 2000, he married Debrah Lee Charatan, a New York real estate broker, but they have never lived together as husband and wife. Mr. Durst did share his fortune with Ms. Charatan, giving her about $20 million from a $65 million settlement of his claims on the family trust. He spent time occasionally with Ms. Giordano and her family. About three years ago, Ms. Giordano said, Ms. Charatan sent her Mr. Durst’s file boxes for safekeeping.
The Houston police, acting at the behest of Los Angeles authorities, searched three apartments on Tuesday that Mr. Durst owns, all at the same address. According to public records, investigators found correspondence with Ms. Giordano, seven credit cards, court documents and two books about his missing wife’s case — “Without a Trace” and “A Deadly Secret.”
An eighth credit card was in the name of Stafford J. Demouchette July 15 Real Estate L.L.C.
The Federal Bureau of Investigation has also reportedly asked agencies in cities where Mr. Durst has lived over the past four decades to review cold cases that might have a connection to him.
The file boxes taken from Ms. Giordano’s home contain the same materials mined by the producers of the HBO documentary, “The Jinx: The Life and Deaths of Robert Durst.” Mr. Durst said he wanted to tell his own story in his own way. Against the advice of his lawyers, he agreed to lengthy interviews starting in 2010, telling the producers, Andrew Jarecki and Marc Smerling, that no question was out of bounds. He also gave them unrestricted access to the files.
“I am convinced that there’s no reason I shouldn’t say anything I want to anyone I want,” Mr. Durst explained in a newspaper interview in February.
Mr. Durst’s only request was that they not bother Ms. Charatan. But in giving the filmmakers unrestricted access to the files, he also provided them with videotaped depositions of himself, Ms. Charatan and his brother Douglas Durst.
In an interview after the airing of the first of the six episodes of “The Jinx,” which featured the depositions, Mr. Durst acknowledged that Ms. Charatan had not come off well. “Poor Debbie,” he said.
The film did not end well for Mr. Durst, who is heard whispering to himself in the closing minutes, perhaps unaware that he was being recorded. “What the hell did I do?” he says. “Killed them all, of course.”
Mr. Durst, who will be 72 next month and is worth an estimated $100 million, has been estranged from his family since 1994, when his father, Seymour, picked Douglas to take over the family empire, which now includes a dozen skyscrapers in Midtown Manhattan.
Kathleen Durst vanished in 1982. Their marriage had become a mix of arguments and violence. Mr. Durst acknowledged in “The Jinx” that he had repeatedly lied to the police about his actions the night she went missing.
After Mr. Durst learned in fall 2000 that the authorities had reopened the Kathleen Durst case, he left New York, renting inexpensive apartments in Galveston, Tex., and in New Orleans, posing as a mute woman.
On Dec. 24, 2000, the police found Ms. Berman dead, shot in the back of the head. Ms. Berman was a close friend of Mr. Durst, having served as his liaison to the media after his wife disappeared.
There seemed to be little progress in solving Ms. Berman’s murder when in October 2001, Mr. Durst was arrested in Galveston over the death of his neighbor, Morris Black. Once Mr. Durst made bail, he fled Texas. He was captured 45 days later in Pennsylvania, and a jury in Galveston eventuallyfound him not guilty of murdering Mr. Black.
About a year ago, the district attorney in Los Angeles reopened the Berman case, partly because of information developed by the filmmakers.
Fearing that Mr. Durst was about to flee the country after he checked into the Marriott in New Orleans under an alias, Everette Ward, the authorities arrested Mr. Durst a week ago in the hotel lobby. In his room, they found a Texas identification card for Mr. Ward, a .38-caliber revolver, marijuana and $46,631 in cash, mostly in $100 bills packed in small envelopes. He is awaiting a bond hearing in New Orleans scheduled for Monday.
Ms. Giordano cannot square the villain described by law enforcement with the man she knew. Mr. Durst had told her before his arrest that he was planning to come to New York after the documentary ended.
“He wasn’t going to Cuba,” Ms. Giordano said. “He had a whole new plan. The plan was, I’ll see you in New York.”
An earlier version of a headline with this article mistakenly described the papers seized by the authorities in the Robert Durst case. The documents belonged to Mr. Durst, not the filmmakers who made a documentary about him.