This is my theory for now:
The kids she ran into at the park were joking around (or maybe being kind of jerks)...maybe something along the lines of playing keepaway. Maybe they took something of hers and threw it in the dumpster. Maybe her phone or something that she would for sure go in after. So she goes in and gets injured or killed and the kids don't know what to do so they tie her dog to the fence to be found (the reports I've read said that KC's mom came upon the dog tied to a fence and that someone who was not there said that someone else told them that KC had asked them to watch the dog.) and split. Maybe they thought she was knocked unconscious and would eventually wake up in the dumpster. Maybe the police are trying to find the thing that was in the dumpster and were waiting on toxicology to see if anything else contributed to her death. The chief of police said "criminal investigation" twice in the pressers but said "death investigation" many more times. This would be a way for it to not be a homicide, for them to have to get stories from a lot of people, for them to have to keep searching the trash for something else, and for them to say no one else is at risk. MOO.