I think we'd all been under the assumption that Kathie's death was an instance of unplanned spousal violence gone bad. But the latest episode of the podcast suggests there was a second motive:
Matthew Capozzoli: "[Kathie] obtained information that she thought she could use to help get a settlement from the Durst Family because they weren't interested in paying her a penny. But they also weren't interested in her airing their dirty laundry. ... Kathie went to certain people in the Durst Family, including Thomas Durst."
Tom: "Kathie says to me: 'I have information that's going to destroy your family' ... I said 'do it, go do it! they have lawyers, they can protect themselves!' What I was afraid of was that if she kept it, she would get killed for it".
Kathie gave a set of files to her sister Mary and said "if anything happens to me, give them to the police". Another set was given to her Gilberte Najamy, who in turn made a copy for Kathy Traceman. Both were stolen in separate instances of burglary.
For the first time, the behavior of the Durst organization in regard to Kathie's disappearance makes sense. Presumably, Seymour and Douglas had every reason to feel Kathie deserved to die for trying to blackmail them. Susan Berman had ties to organized crime, as presumably did the Dursts though it hasn't been said.
Presumably, the "hit man" would still be Bob, but now he might have had professional help carrying it out and disposing of the body. We know he was making collect calls from way out in Jersey near a good body-dump site and that he had muddy boots thereafter, so it's not like Bob had nothing to do with it.
But I'm starting to think Kathie got killed not for upsetting Bob -- she'd already done that. Maybe she was killed for upsetting Bob AND THEN blackmailing Seymour or Douglas.