This case reminds me mostly of Katelyn Markham. She went missing as of midnight, her boyfriend was elsewhere but had been the last to see her and last person on her phone. LE said they had no idea if a crime had been committed until her remains were found about 18 months later, over a state border about 25 miles away. No one has been arrested as yet, another 18 months or so later. She too left her dog behind. TES went there too (Ohio) and did a similar search, mostly a radius out from her apartment, last place she was known to be, and left, saying they would return if evidence or tips warranted it.
LE can only do so much. They need something to go on. They interviewed the BF in Katelyn's case many time, lots of other people, thought they had a hinky neighbor but he was later ruled out. But they always said they did not know if a crime took place and I guess it was mostly true. Much like Hailey Dunn as well. Lots of people thought an arrest would come as soon as a body was found, but it hasn't happened, again maybe 18 months ago or longer since she was found. Cause of death may not have been available due to length of time, but but were clearly murdered by how they were found.
Not all of these cases come to a conclusion.
Jmo