Should be pretty easy to know what rounds were used, unless the shooter policed his brass (and then dumped them someplace not visisble).
I doubt incompetence on the part of the media.
Throw enough BS out there and then later pick what you want your story to be.
Actually it is pretty straigthforward (in the specific example of the firearms), if a rifle was in the trunk it was in the trunk.
Then you over estimate the media. I've been on multiple scenes were I later saw a news report about it and said...that's kinda close to what happened but wow are the details wrong.
Keep in mind the media aren't looking at the brass themselves. They are "overhearing" things, getting things second and third hand (investigative officer tells the media affairs officer who tells the chief, etc.)
Journalistic integrity has been replaced by journalistic expediency. In the days of print news, you could take your time, verify sources, basically get things done right and be reasonably sure of your story. CNN, Fox, and the first Gulf War began the end of that way of doing journalism for the masses. Instant Internet news strangled the survivors. Now it's not about who's right, it's about who's first.
Just report SOMETHING so you can be first, then sort the facts out later.
Wow. That is suspicious about the RIP Facebook page. That is about as eerie as the Sandy Hook reference in the Batman movie. I wonder if we'll find more oddities as this unfolds.
The nonconspiracy explanation is that Lanza targeted her and created the page himself...