Oswald made an arrest legal by taking the first punch (as Brewer testified). No one had a clue if he had shot anyone at that point (if some did, by all means do post that info). Try to keep up: The police were dispatched to cover all reports of suspicious-looking activity as seen by alert citizens. It was a manhunt, FFS.
Oswald made an arrest legal by taking the first punch (as Brewer testified).
They didn't arrest him for "taking the first punch" -- they arrested him for murder. And the check boxes on the arrest report for "fought", "resisted", and for "officer injured" are not checked.
That is indeed what it states.