Wednesday marked 42 years since Kathie Durst, the former wife of real estate scion Robert Durst, mysteriously disappeared.

Robert Durst has been accused of a string of killings across the country over four decades – including his wife, Kathie.

Our senior reporter Tara Rosenblum brings us up to date on her family and how one former detective continued to fight for justice beyond the grave.

Joseph Becerra was still in high school the day medical student Kathie Durst vanished from her South Salem home in 1982.

But 17 years later he received a tip from a flasher while on the job as a state police investigator that would forever alter the course of the widely publicized disappearance of the 29-year-old.

“It started with a tip on some individual that I arrested, and it just piqued my interest, and I started looking into it and I was just bewildered,” he says.

Becerra reopened the case, which ultimately involved a string of killings in several states, multiple trials and decades of intense media coverage.

“I don't know if it's a police intuition. I just feel that based on looking into this case for so long, and the interviews that were conducted, that there is no one else other than Robert Durst who is responsible for her death,” he says.

Shortly before his death last year, Robert Durst was convicted of murdering his best friend, Susan Berman in California and then indicted in Westchester County in the killing of his wife Kathie, nearly four decades after she was reported missing.

“There was a lot of painstaking work that went into the case by a lot of detectives,” he says. “I think the undoing of all for Durst was the fact that he decided to talk to the media, and things he said got the ball rolling in Los Angeles.”

Los Angeles officials charged Robert Durst with a special circumstance murder, meaning that he murdered a witness.

“That witness would have been Susan Berman, who would be a potential witness in our murder investigation in New York,” he says. “He basically put the Kathie Durst murder case on trial in Los Angeles. Once he got the conviction out there, we continued working the case. “

Weeks later, Westchester District Attorney Mimi Rocah announced her cold case unit had secured enough evidence to convince a grand jury to indict him. Durst died a few weeks later before the case went to trial.

“When Robert Durst was indicted in Westchester County, there was a huge sense of relief,” Becerra says. “Unfortunately, the one thing that I wanted to find out was where Kathie was buried…Kathie came from a middle class, Irish Catholic family and that's really what they wanted in the end…closure. They wanted to be able to bury her properly. And I couldn't give that to them.”

Becerra says there were a lot of things that came out through the Los Angeles trial that made them more confident that he could secure a conviction in New York.

“There was no smoking gun per se, but just as actions as activities his traveling. I can't answer why there wasn't a grand jury indictment prior,” he says.

Kathie Durst's family continues to fight for justice - despite Robert Durst’s death -- as a wrongful death civil suit winds its way through the courts of Westchester County.

The family hopes it will unearth the evidence that has been long shrouded in secrecy.

Robert Durst left his fortune to Debrah Charatan, his wife at the time of his death. Kathie Durst's family filed a wrongful death action against Charatan, in her capacity as the nominated executor of Robert Durst's will.