Unasked questions (spoilers)

I was wondering, too.

I did a bit research and different sources tell different stories. Allegedly he admitted that he retrieved the head the next morning to dispose of it somehow, but if I got that right he claimed he cannot remember where claiming he was so drugged up.

My theory is that his lawyer told him to say he cannot remember cause the head would have been the smoking gun at court. No other body parts had a gunshot wound, so I guess he shot him in the head. If they found the head they might would have been able to prove that it wasn't an accident. So his defense team maybe told him to not reveal where he eventually got rid of it.

At some point in The Jinx he mumbles something like "I didn't knowingly, purposefully lie, I just didn't tell everything." or something like that and afterwards his lawyer reminded him that everything can be heard.

When the talked about the trial Durst also mentioned that his lawyer told him to say he cannot remember any details claiming he was too drugged - therefor I bet his lawyer told him to say the same to Jarecki. I can't imagine Jarecki failed to ask. He just didn't get an answer.

They cannot do much when he says he cannot recall it. Blows my mind, too.

While Eugene Jarecki is no Trey Gowdy, he's not at all a stupid man. Perhaps Durst told Jarecki straight up if he went there he (Durst) would walk away from the project, never to return?

I know what you mean. Furthermore, I was frustrated by there being little to no mention of the forensics at the crime scenes. That topic probably could have filled up an episode on its own.

I think at the beginning, Jarecki had a 'gently gently' approach. He didn't ask too many probing questions for fear of Durst backing out. In fact, Durst pretty much had backed out until he needed the film-makers on side for helping him with his arrest for trespassing, so gave them a second interview. I think Jarecki knew it would be his only opportunity for a more interrogation-style interview, and he agonized over how to approach the letter handwriting issue, afraid Durst would not answer and realize they were not on his side. So, keeping his interviewee happy was his main objective as it's the only way he'd talk.