Thanks for the great photos. What I find interesting about them is that it can be determined exactly where the offender stood on that welcome mat, based on the small B/W image. Would there be anything to find there? I have no idea, but to leave the mat and not even keep the crime scene tape up just shows carelessness on the part of PCSD.
Unfortunately, with all of their internal conflicts, they are the lead in this investigation.
I think we have to be a bit realistic here. In most cases, police run forensics, then hand the property back. In all the murder and missing persons cases I have followed, crime scenes are not maintained as sealed off crime scenes for any length of time. It's simply not practical, and often people live in those places.
Also, I've seen in multiple cases that forensics have returned to a scene and recovered evidence. It happens. But I don't think we can blame LE for this. Mostly scenes are photographed and sampled. They don't usually take away the contents unless it's something quite specific.
IMO