These are good, fair, necessary questions.
The more closely we look, this does seem to be a kangaroo court thing. You can't put a man on trial in peril of his life or freedom, forcing him to spend lots of money to hire attorney, experts, etc to prove he didn't do it, with evidence this weak. REASONABLE cause means there's enough evidence that it's "reasonable" to think a jury might convict. But with this bag of bricks they've collected, and the obvious gaping holes, it's fairly absurd. imo anyhow
A man is dead. Kelly is a possible suspect. But there is NO physical evidence, there are other reasonable suspects, and the only witnesses they have offer stories that contradict themselves and the facts of the case. They need way way way way more to take this to trial. Goodness, at this point, they can't even prove it was a bullet from Kelly that did this.