If there is a DNA profile to help identify a potential suspect in Molly Bish's case, then that also probably means that there is a DNA profile to help exclude possible persons of interest known to the investigation. People like the sand truck driver, the work supervisor, and other potential persons of interest that have come up during the course of the investigation could be excluded based on this DNA evidence. I am guessing they probably already have been.
The only thing I really ever came to any sort of personal conclusion about in this case was the possible location of a suspect. When Molly Bish's bathing suit was found by the hunter and the ex-police officer detective, they said they went to the town of Ware to get the police and report it. That is where I would have thought her killer lived at the time because it seems like it is the closest residential area. Whiskey Hill does not seem like the type of place someone would just happen upon to place a body, in my opinion. The news said this new main suspect Sumner lived in Spencer, MA although maybe he did not live in Spencer at the time of the crime.
I was always a little suspicious of the work supervisor, but mainly because of the story of him first learning of Molly Bish's disappearance at the pond. He then radioed the police with Molly Bish's two way radio at 11:44 am from the pond area. Then he must have left and ran into her brother at the hardware store without mentioning Molly was missing?
My theory was that the work supervisor drove to somewhere near Ware, Palmer area to drop off the lifeguard, then drove back to the pond, but stopped at the hardware store in case anyone noticed he was not painting the fence.
When you do not have all the information regarding facts and sequences it is so hard to correctly understand a story. A person's reaction to a given situation is not evidence. At least now in this case people that may have been suspected for a long time can be cleared.
Hopefully this is the year Molly Bish's case comes to a conclusion.
If you do a Whitepages (or similar) search on the suspect's name, you will see that he lived in multiple places all around the area, including some that are 18 minutes or less from Whiskey Hill. I think he was close enough to be aware of the area, especially if he ever had an interest in hunting or knew people who did.
Also, according to this article: Molly Bish murder suspect’s family demands Worcester DA provide proof; Early cites information from ‘last several months’ - The Boston Globe
We learn that while he is newly named as a suspect, he was not new to investigators. His family indicated that he was already on LE's radar 4 years after the crime. Whether that is because of his locality and previous convictions for kidnapping and rape, or because LE had tips on him, or some other reason, we do not know right now.