NewsNation reported it. Also, a couple of outlets reported that Kohberger had "slid" into her DM's on Instagram (her Instagram is still up, although a few things may have been edited). He did this three weeks before the murders (per NewsNation who reported it before the gag order, perhaps the family members were still speaking off the record). Apparently, it was his actual account.
At any rate, we can't know whether NewsNation is reliable, but I suspect they are. Since the gag order, I've noticed that they are relying mostly on sources outside the gag order (which only reaches people in the State of Idaho - the Idaho judge cannot gag people in Pennsylvania or Washington, is my understanding).
On the forensic side, I have often wondered if they used forensic radiology (something the U of Washington has pioneered - and the ME where the autopsies were done has a state-of-the-art facility, nearly brand new, all the equipment one needs). This would be cutting edge use of their tools, as it would be able to locate microscopic metal fragments in the wounds, allowing some form of spectometry as to the chemical composition of the particles.
I also want to say that
@Sister Golden Hair 's analysis of the search warrants leads me to believe they tracked down where he bought the knife <<< true that that's speculation, but I find it compelling. I also find it easy to believe.
And then there is the wider net of cell phone tower information (aside from the main towers in Moscow) AND the GPS data from his phone (which surely corroborates the ping data).
I just wish we knew how long it took to present the evidence to the GJ.
IMO.
