User blog comment:Olaf-Tiffi-Odus2711/Kitten Detective - Round 3/@comment-7106186-20150207162401

The killer is from world 5... there's only 3 of them from world 5 :

cat, gator and minty

they know kung-fu, but gator doesn't have any insanely hard level.

cat and minty are the only one, however, cat has a building in her episode.

so the killer is Minty!