In 2006, it looked like the longstanding acrimony between Robert A. Durst, the real estate scion, and his family was coming to an end, with one final separation. Just a few years after being acquitted of murder despite admitting to dismembering a neighbor in Texas, Mr. Durst agreed to cash out his stake in the family skyscrapers for about $65 million.
But Mr. Durst, 70, was arrested Friday morning outside his Harlem home after showing up twice at a nephew’s home on West 43rd Street, the police said. Mr. Durst had previously been warned to stay away, and his brother complained to the police, the authorities said.
The charge is for trespassing — a violation, not even a misdemeanor — but it comes as investigators are digging once again into Mr. Durst’s past. Agents with the Los Angeles office of the Federal Bureau of Investigation have been in New York to speak with relatives and old friends of Mr. Durst’s in recent months.
People familiar with those talks say that the investigators seem to be exploring whether Mr. Durst might have had a role in the 2000 killing of Susan Berman, an author and the daughter of a mobster, who was found dead in her Benedict Canyon home in Los Angeles. One of Mr. Durst’s closest friends and confidantes, she had been shot in the back of the head. At the time of her death, the authorities had been seeking to interview her about the 1982 disappearance of Mr. Durst’s first wife, Kathleen, who was never found and is presumed dead. Mr. Durst has never been charged in either of those cases.
Mr. Durst has long been estranged from his family. The rift widened when the family patriarch, Seymour Durst, chose Robert’s younger brother, Douglas, over him to head the family business in the mid-1990s.
By 2000, Mr. Durst had moved to Galveston, Tex. Posing as a mute woman, he rented a modest apartment across the hall from a 71-year-old former merchant seaman, whom Mr. Durst was eventually charged with murdering and dismembering. Out on bail, Mr. Durst became a fugitive before being arrested in eastern Pennsylvania. But while he was on the run, he pulled into the driveway of the Westchester County estate of his brother, Douglas, with two loaded handguns in his car.
Sent back to Texas for his trial in 2003, Mr. Durst testified that he and Morris Black, the former seaman, had been struggling over a pistol when it went off, killing Mr. Black. Mr. Durst testified that he panicked and dismembered Mr. Black, disposing of the body in Galveston Bay. The jury acquitted him.
Yet federal investigators, apparently skeptical of the verdict, are also investigating whether there was jury tampering in connection with the trial in Galveston, said one person who had been interviewed by the authorities.
In the last year, Mr. Durst closed up a residence in Los Angeles and he is now spending more time in New York. In April 2012, as he walked along West 43rd Street, he was spotted by a security guard for his relatives, who warned him to stay away. His brother’s son Alexander has a residence on the street.
In June, the police said, Mr. Durst walked up to the stoop of the residence and peered into the building (and at least one video surveillance camera). It was that episode that led to his arrest on Friday, the authorities said.
He was arraigned Friday on the trespassing charge. Attempts to reach a lawyer for Mr. Durst were unsuccessful.