When I look at the images you have provided of shoes of an unknown person they don't look like the shoe soles of the POI. I don't see a black diagonal reinforced area to the white sole of the POI's shoes. Singling out an individual because the shoes they are wearing are black with white soles means several hundred thousand people who own shoes like that, me included, are now considered POI's? If you think this person could be a valid POI, please advise LE and let them do the investigation.
About a knife being used in the murder. If it was a knife, we have no idea if it was a kitchen knife with a serrated blade or a wide blade like a chef's knife. If it was the perp's knife it could be a drop point, a dagger or a Bowie knife. After guns, knives are the next cause of death. Since many knife murders are domestic in nature, kitchen knives rank high in cutting instruments. All those different knife blades leave different entry wounds. Until LE release the type of injuries inflicted on SR we can only speculate on cause of death.
If the suspect(s) attempted to clean the crime scene I would presume a knife (if that was the murder weapon) would also be cleaned. If bleach was used to clean the crime scene, most homes have bleach as a cleaning agent in their homes so it's unlikely the perp brought their own. Cleaning up could have been as simple as taking a shower to clean up residual blood spatter on their own person.
I initially wondered if the POI was a female but after reviewing the video umpteen times I believe it is male. I still wonder if the funny little hitch in his walk is because he's injured. An up close and personal murder can inflict injuries on the killer, especially if the attack involved close contact. Because SR was found in his bedroom the obvious place a person considers the location of death is the bed but that's not necessarily so. If a person was killed in their bed especially if their death was a violent one it would be almost impossible to clean up, IMO.
It's kind of unusual that there is absolutely no follow ups to this murder investigation since January of this year. I can't find one news outlet with an update. I don't know if that means the investigation has run out of steam or they are building a case against a likely suspect.
It must be very frustrating for the family to see that Scott's murder appears to be old news now. However, the fact that they remain quiet on the subject makes me hopeful it's because the investigation is making inroads. I have heard rumours about this murder, though.