keywordp & :killing-the-cat

[MON KEY]

How does one test whether a symbol is a keyword?

(keywordp :killing-the-cat-with-epr) ;=> t
(unintern :killing-the-cat-with-epr) ;=> t

(mapatoms (lambda (x)
            (when (eq x :killing-the-cat-with-epr)
                (prin1 `(found ,x))))
                  obarray)

;=>(found :killing-the-cat-with-epr)

Is this because keywords are self quoting?
And if so, how does one use keywordp to test if a (possibly
non-existent) keyword is interned without interning it?

i.e. (makunbound :killing-the-cat-with-epr) ;-> Lisp error:
(setting-constant :killing-the-cat-with-epr)

s_P