I am not going to speculate. I just listened to a source I trust, that if the “suicide” was in doubt, they’d be a toxicology exam and they take time.
Toxicology would take time if the “suicide” was some normal Joe on the street, in there for a DUI. In a high profile case like this, EVERYTHING, stops. Unfortunate, but true. All testing, for all other cases will be put on hold to get this done.
Mass spectroscopy doesn’t take much time to run a specimen. At maximum, if you run liquid chromatography with mass spec your looking at less than an hour. Now if you have a special case, you may want to re-calibrate the machine just for that specimen so at most you’re looking at one day.
I would hope that they used a second laboratory as a check. Of course, sample custody can be compromised at any time during collection to running the sample.
Transportation and handling is the thing that takes the most time, but they would have priority here.
Lots of room for government chicanery no doubt anywhere in the process; that’s what takes time.