as ex-marine walter , who may or may not have shot kennedy , actor raymond j. barry is perfectly creepy and believable . 
(ROOT (S (PP (IN as) (NP (NP (JJ ex-marine) (NN walter)) (, ,) (SBAR (WHNP (WP who)) (S (VP (MD may) (CC or) (MD may) (RB not) (VP (VB have) (VP (VBN shot) (NP (NNP kennedy))))))) (, ,))) (NP (NN actor) (NNP raymond) (NNP j.) (NNP barry)) (VP (VBZ is) (ADJP (RB perfectly) (JJ creepy) (CC and) (JJ believable))) (. .)))
(ROOT (S (PP (IN ) (NP (NP (JJ ) (NN )) (, ) (SBAR (WHNP (WP )) (S (VP (MD ) (CC ) (MD ) (RB ) (VP (VB ) (VP (VBN ) (NP (NNP ))))))) (, ))) (NP (NN ) (NNP ) (NNP ) (NNP )) (VP (VBZ ) (ADJP (RB ) (JJ ) (CC ) (JJ ))) (. )))