If the police are denying the two cases are linked, let's define "linked".
The people ARE in fact linked. HG, SF, MH and JR all worked at Allen Organ but some at different times. Is there a deeper connection than just co-workers?
Are HG and SR linked? Both Allen Organ employees (but not at the same time). So maybe they did not know each other. But other people knew them both.
Motive for HG disappearance and SR murder? Non reported by police to date. This is the link that's missing. One person murdered SR and another with the disappearance of HG. Same person or different?
There's too many coincidences. The same workplace, all in the same age range (40's). And coincidentally, three of the four players here (the fourth is unknown at this time) have/had gotten DUI's. So most were the same age, same workplace, and drank at bars. Did they know each other from a bar? This may really, REALLY be grasping at straws, but one of the closest bars in that area would be the Buckeye Tavern (which coincidentally is located right next door to someone important to Holly) It burned down in 2015. From what I was able to find so far, they know where it started, but had a hard time determining how. Now, there was another fire at Stephanie Roof's house as well. Just a bit strange that fires/arsons occurred at or nearby people involved in these cases.