Last week, News 12 introduced viewers to the ex-husband of first lady Jill Biden - who revealed a romantic connection to the wife of alleged killer Robert Durst, just a few days before she went missing.

Since its airing, the exclusive report by Tara Rosenblum has circled the globe - from Texas to Russia - as Delaware businessman Bill Stevenson revealed that he sees himself as the missing link in the closely scrutinized, decades-old cold case.

News 12 has also heard from the family attorney of Kathie Durst, Robert Durst's missing wife.

Robert Abrams said in part, "The information provided by Mr. Stevenson added to the overwhelming evidence that Kathie Durst was intentionally murdered by Robert Durst. It is our sincere hope that prosecutors in Los Angeles County and Westchester County have spoken to Mr. Stevenson. However, if they have not, we urge them to do so immediately to secure his critical testimony regarding one of the motives for Kathie's murder."

Stevenson told Tara Rosenblum exclusively that he had an affair with Kathie and was confronted by Robert Durst the following morning, just 10 days before she vanished from South Salem.

Durst is on trial in California right now for the murder of his best friend Susan Berman.

The Los Angeles District Attorney's Office would not say if Stevenson will be called as a witness.

News 12 received a similar response from Westchester District Attorney Mimi Rocah, who reopened a murder probe into Kathie's death several months ago but has yet to empanel a grand jury.

Stephenson says he hopes his story will help Kathie's family get justice after four decades.

Dick DeGuerin, Robert Durst's attorney, told News 12 that "It’s inappropriate for me to tell you what I think about it, since we’re in the middle of trial."

Stevenson also revealed that his former wife, now first lady Jill Biden, had an instant and close friendship with Kathie Durst. News 12 reached out the first lady's press secretary three times since last week. Tara Rosenblum asked if Kathie Durst ever confided in Jill Biden about her troubled marriage to Robert Durst or if Jill Biden ever had contact with Kathie Durst's family after she went missing in 1982.  The press secretary acknowledged he received News 12's emails but has not answered questions yet.

News 12 is also waiting to hear back from the White House.