Crime Relatives of Robert Durst's Missing First Wife Petition Judge to Declare Her Dead "There is a strong probability that Durst killed Kathie," the missing woman's sister, Carol Bamonte, argues in court papers By Chris Harris Chris Harris Twitter Chris Harris has been a senior true crime reporter for PEOPLE since late 2015. An award-winning journalist who has worked for Rolling Stone and MTV News, Chris enjoys prog rock, cycling, Marvel movies, IPAs, and roller coasters. People Editorial Guidelines Published on April 1, 2016 06:10 PM Share Tweet Pin Email Photo: Reuters/Landov The family of Kathleen Durst, the first wife of real estate heir and alleged murderer Robert Durst who went missing in 1982, is petitioning a New York court to formally declare her dead, according to court papers obtained by PEOPLE. The papers were submitted by Kathleen’s sister, Carol Bamonte. Late last year, Kathleen’s family filed a multimillion dollar “right of sepulcher” lawsuit, claiming Durst has denied the family its right to choose a method of burial for their relative, who, they say, is deceased. Kathleen’s other sisters, Mary Hughes and Virginia McKeon, claim in their own filings that they’re convinced their brother-in-law killed his wife at the couple’s weekend home in South Salem, New York. • Want to keep up with the latest crime coverage? Click here to get breaking crime news, ongoing trial coverage and details of intriguing unsolved cases in the True Crime Newsletter. They further allege in their petitions that Durst illegally disposed of her remains, which have never been recovered. In her affidavit, Hughes says her earlier suspicions that Durst allegedly killed her sister “could not be substantiated to the satisfaction of this court, the police, and most importantly, my mother” until the airing of an HBO TV documentary on Robert Durst. In court papers, Bamonte claims that a formal declaration of her sister’s death is needed before Kathleen’s family’s lawsuit against Durst can proceed. “There is a strong probability that Durst killed Kathie,” Bamonte argues in court papers, calling the 72-year-old “a violent criminal who had physically beaten Kathie on numerous occasions before her disappearance.” Kathleen had been declared dead by a judge in 1988, but only for limited insurance purposes, according to records. Robert Durst faces murder charges in Los Angeles in the 2000 death of his longtime friend and spokeswoman, Susan Berman. Durst is currently being held in a Louisiana prison after pleading guilty in February to a single gun charge in federal court in New Orleans. The millionaire will likely be sentenced to serve 7 years during a hearing set for April 27. He’s to be extradited to California before September, according to officials. Durst ignored his attorney’s advice and served as the subject of the Emmy-winning HBO documentary series, The Jinx: The Life and Deaths of Robert Durst. The series focused on Kathleen’s disappearance and the death of Berman. During filming, Durst allegedly muttered that he’d “killed them all, of course.” He was allegedly unaware the filmmaker’s microphones were still recording at the time. While initially identified as a person of interest in the case, Durst has never been charged with his wife’s murder.