IIRC way back in the thread some of the sleuthers here did look up past incidents in the park. Have you read the whole thread? I know it's a lot to go and read over.
Anyways I can't remember there being anything that stuck out as something that would relate to Karinas murder. Back in the day that specific area the mob used the park as a disposal site for bodies/body, again that's IIRC. IMO I do not think that relates to Karinas case at all.
I had heard that the park was a dumping ground for bodies back in the 1930's... the only unusual thing about that area is that a man who lived near KV was found hanging there. It happened in the summer before K. was killed. Ruled a suicide.
Otherwise it seems populated by homeless people, and substance abusers. Difficult to imagine someone from the latter two groups doing this and getting away with it. JMO, though.