The thing about doing this on the internet and not in person is often time we don't know what the actual facts are. The JR case the scanner information and the most recent Denver Post article and then the Fox 31 article and then the LE saying 60 percent was bad. We really don't know what LE knows in that case at all so theories are all that anyone on here has.
I’m not sure about the cases you’re referencing, I am referring to the practice of web sleuthing in general. Facts can come from a variety of sources -- public documents, court docs, press releases, photos, maps, business records, property records. As well as weather, proximity, time/timing, place, and a variety of logistical considerations. All of these are sources for facts for individual cases. In Whitney’s case, there are plenty of verifiable facts to sleuth. The timeline, place, and proximity alone are enough to keep on sleuthing. In active cases of course not all facts are given to the public - nor should they be.
In my opinion, if there is an official public document on probable cause -- you work the details of that document, however scant they may be. Where people run into trouble is when they don't cite sources or get the info wrong and no one corrects them. Or theorize with no factual basis. Those are the root of poor quality results and criticism.