Who is MCSO?
It is SDSO/DOJ/FBI that conducted the seven-week long investigation into Rebecca's death. And when fifteen detectives are working on the case, that is a very long investigation. Especially when you consider that the PHYSICAL evidence that proved it was Rebecca and only Rebecca in that room came back fairly early in the investigation.
When the fingerprints, and DNA, as well as other physical evidence PROVES it was a suicide, then everything else was just to FURTHER VERIFY that NO ONE else was there during the time of Rebecca's jump.
This is not to find out "what happened that night". The Zahaus claim they already know that, and have brought SPECIFIC charages that they will not be able to PROVE because they are CONCOCTED and IMAGINED.
This is also not to find out why Rebecca was left uncovered (which, btw, is standard when the method of death is not known) - further proof the detectives did not "rush to judgement".
This is about $10 Million dollars. And IMO, it will be dismissed in May, once the Judge reviews the "evidence" the Zahaus have to date verses the "evidence" the SDSO has proving Dina, Nina, and Adam had nothing to do with Rebecca's suicide.