I don't know that much about the US system, for instance we don't have grand juries over here (UK). At the arraignment hearing, the October 20th hearing was described as a "Probable Cause hearing", and I was hoping someone here would explain a bit about that to save me looking it up. While they were discussing that next hearing with the judge, they were also talking about the coroner's report, and I think they're hoping to have further information on the COD by them, so my conjecture was that it won't be too different from the arraignment just with more detail on why they want to continue holding these people and to send them to the grand jury? But I presume most of you know far, far more about this stuff than I do! Maybe someone could explain some of this now, as I've seen it asked several times.
Amonet, you did a great job with your explanation of what occurred at the arraignment. Actually, here in the states, it can sometimes differ from state to state, but for the most part the same. Yes, It is called the Great Commonwealth of Massachusetts as you will hear it called before court when this finally gets there, and if it is streamed (hopefully!). But that is a LONG way off.
There will be many hearings as this goes along, and many will be delayed to a later date. They are still investigating the crime scene, etc., and are waiting for a COD from the coroner, which may take a while as he/she also considers evidence that LE comes up with, especially with a deteriorated body. After the investigation is complete, LE works with the prosecution team and their case is presented to a grand jury, which will vote to what charges will be formally made against the defendants. Then there are MANY hearings prior to trial of what evidence can & cannot be presented. Then the real trial.
Hope this help a little.