NEW YORK (AP) — A New York prosecutor will seek an indictment in the coming weeks against millionaire real estate scion Robert Durst for the death of his former wife, Kathie Durst, who disappeared in 1982, a person familiar with the matter told The Associated Press on Friday.

Westchester District Attorney Mimi Rocah decided in recent days to take the case to a grand jury in the next week or two, according to the person, who was not authorized to speak publicly about the matter and did so on condition of anonymity. The grand jury process is expected to take about a month, the person said.

The news was first reported Friday by News 12 in Westchester.

Kathie Durst’s disappearance has shadowed Robert Durst, 78, for years, highlighted in an HBO documentary in which he appeared to admit killing people and culminating last month in his conviction in California for murdering a confidante whom prosecutors say helped him cover up Kathie Durst’s killing.

A message seeking comment was left Friday with the Westchester district attorney’s office, which previously said that it reopened the investigation into Kathie Durst’s death. In a statement issued after Durst’s conviction last month, a spokesperson for Rocah’s office said its investigation was ongoing.

Durst’s lawyer, David Chesnoff, said: “I don’t respond to rumors.”

Robert Durst is jailed in Los Angeles and scheduled to be sentenced Oct. 14 for the 2000 killing of his friend, Susan Berman. His first-degree murder conviction carries a mandatory sentence of life in prison without the possibility of parole.

Durst, the eccentric heir to a family of New York City developers, is now sick and frail. He sat throughout the trial in a wheelchair, spoke slowly in a strained, raspy voice when he testified in his own defense and read his lawyer’s questions from a tablet giving live transcriptions because he struggles with hearing.

Los Angeles prosecutors say Durst shot Berman at her Los Angeles home in December 2000 as she was preparing to tell police about her involvement in Kathie Durst’s death. She had told friends she provided a phony alibi for him after his wife vanished, prosecutors said.

“He’s a narcissistic psychopath. He killed his wife and then he had to keep killing to cover it up,“ Deputy District Attorney John Lewin said after Durst’s conviction in the Los Angeles case.

Kathie Durst was 29 and in her final months of medical school when she vanished on Jan. 31, 1982. She and Robert Durst, who was 38 at the time, had been married nearly nine years and were living in South Salem, near the Connecticut border. Her body was never found. At the request of her family, she was declared legally dead in 2017.

Robert Durst claimed to police that on the night of her disappearance, he’d put her on a train to New York City, had a drink with a neighbor and then spoke with Kathie Durst by telephone while she stayed at their Manhattan apartment. They’d been fighting earlier in the evening, he said. A few weeks before that, Kathie Durst went to the hospital with facial injuries she said were caused by Robert Durst.

In the 2015 HBO documentary “The Jinx: The Life and Deaths of Robert Durst,” he admitted he made up the details about seeing his neighbor and talking to Kathie Durst by phone, saying he did so because he was “hoping that would just make everything go away.”

In the same documentary, after filmmakers confronted Durst with evidence linking him to Berman’s killing, he stepped off camera and muttered to himself on a live microphone in the bathroom: “Killed them all, of course.”

Robert Durst, who divorced Kathie Durst in 1990 citing abandonment, has never been charged in her disappearance despite several efforts over the years to close the case. Authorities reopened the case in 1999, searching a lake and the couple’s home.

While all that was happening, Durst fled to Galveston, Texas, where he was accused of killing a neighbor, Morris Black. Durst then chopped up Black’s body and tossed it out to sea. Durst claimed self-defense — that he and Black were struggling for control of a gun — and was acquitted. He was convicted of destroying evidence for discarding the body parts.

Durst, testifying in the Los Angeles trial, denied killing Kathie Durst. After her medical school called to report that she hadn’t been going to class, he said he figured she was “out someplace having fun” and suggested that perhaps drug use was to blame.

“It hadn’t occurred to me that anything had happened to her,” Durst testified in August. “It was more like: what had Kathie done to Kathie?”

Associated Press reporters Brian Melley and Andrew Dalton in Los Angeles contributed to this report.