Coupla thoughts.
First, robbery or burglary is still a crime even if the item is later returned. At least I believe so.
The example from a case near me was a perp using the victim's own car to transport her body. He later returned the car (and presumably the keys) but it's still burglary. Of course the murder is the primary crime but sometimes there are reasons to include the other charges as well.
I really hope LE has checked out KB's vehicles for any evidence they may hold.
Snipped by me. There's that Sept date again. Maybe the range of dates is correct as filed, intended to give a general timeframe only, and then the database couldn't display a range of dates so only the first date, the 9/01/18, was listed, creating the "clerical error".
Another thought: If the robbery had actually been successfully completed, wouldn't there be a charge for it as well? If so, that suggests that the robbery was only attempted, and she died in the process, but nothing was actually stolen.
ETA: it seems that the definition of robbery doesn't actually require anything to be taken, it's simply unlawful entry for the purpose of committing a crime? Attorneys can maybe clarify?