Are there more than one person? No.
- If there is one person, is that person the murderer? Yes.
- If there are more than one person, are there two? Three? Even more? N/A
- Is the gender of the person(s) relevant? According to the answer, it's a man, but it's not terribly relevant.
I guess we take the beach one then? See note below.
Is it relevant how high on the beach the corpse is? No.
Was the corpse beaten to death? Sorta. (Don't really like the word "beaten.")
Is the motive behind this relevant? Yes.
Was the corpse previously tortured? No.
About the beach... It might be easier to solve in the long-run if you found a 'more distinct' location. But it might be easier to find that location if you found other things first, I'm not sure. I'll leave it up to you what line of questioning you prefer for now.