It was an unusual relationship.
Robert Durst once reportedly dated actress Kim Lankford, best known for her role in Knot's Landing, the eighties prime-time soap opera.
They reportedly went out for 18 months, but he suddenly ended the relationship when he announced he was marrying second wife Debrah Charatan in 2000.
Former Texas judge, Susan Criss, who presided over the trial in which Durst was acquitted of murdering a neighbor, says Durst was overheard threatening Kim Lankford during a taped jailhouse conversation with his wife.
"He's gone on a cruise with an actress named Kim Lankford and she [Berman] was very upset about that," explained Criss. "He explained to her that although he had gone out with Kim Lankford he had not had sex with her because he had only had sex with prostitutes. And that didn't seem to be a problem."
Judge Criss told INSIDE EDITION, "He was angry at Kim about something and he makes the comment, 'I could just beat Kim,' and his wife tells him to stop talking because this is a recorded line." "I could beat Kim?" "I could just beat him."
Kim Lankford was featured in The Jinx because she was also friends with Susan Berman and spoke to her just days before Berman was allegedly executed by Durst.
"She was going to blow the socks off something. I said, 'What?' She said, 'I can't talk about it right now but something big is going to happen.'"
"What do you mean? What information?" Lankford asked.
"Well, I don't have it myself, but I know how to get it," replied Berman.
"Well, be careful, for God's sake," said Lankford.
Prosecutors believe the 'something big' was information about the death of Durst's first wife, Kathie, who disappeared in 1982 and some believe is dead, at the hands of Durst.
Judge Criss believes Berman, "...had something explosive to say that was going to blow the lid off everything!"
Durst's attorney says he had nothing to do with the death of Susan Berman or his first wife.
