Can you show us any evidence?

Yeah I'm not an investigator with any manpower or authority to go looking for evidence, doesn't mean its not out there. Suspicious enough to start looking in my opinion. The non-circumstantial evidence has to be looked for it doesn't just appear.

I'd guess not as nobody wants to be the judge (or jury member) they find themselves also criminally liable for murdering.

With only some circumstantial evidence? Almost certainly not.

Virtually all evidence presented in courts is circumstantial (including DNA, fingerprints, etc.), eyewitness testimony of the actual crime is pretty much the only thing that isn’t.

If they have anything like that then there might be the case, but so far all that is publicly known is that Boeing plausibly had a motive for wanting them dead. No sane prosecutor will try their luck with only that to go on.

So the argument is that’s it’s weak evidence, not circumstantial. Circumstantial evidence is often the strongest kind.

What circumstantial evidence is there besides motive?

None that I know of, so I don't expect anything to come of it unless there's something more the public hasn't heard about. You can't reasonably expect a murder trial with that little to go on. They don't even have homicide listed on the death certificates.