Palestinians have no authority or legitimacy in israeli closed military zones also known as settlements. They are run and controlled by IDF. Also who is left to arrest after all the mass arrests of anyone remote suspect by any reason? It's an israeli controlled military zone! The question is how could the killings have happened at all, and why settlers are allowed to endanger and use their children as human shields in an cruel and unjust occupation.
from the article: Israeli police arrest six suspects in murder of Palestinian teen