(S (S (NP (BASENP (NN One) (NN witness)) (PRN (COMMA ,) (SBAR (WHNP (WP who)) (S (VP (VBZ has) (VP (VBN been) (VP (VBN identified) (PP (ADVP (RB only)) (PP (IN as) (BASENP (NNP Chris))))))))) (COMMA ,))) (VP (VP (VBD informed) (BASENP (DT the) (NNP BBC))) (PP (IN of) (NP (BASENP (DT the) (NNS events)) (SBAR (S (BASENP (PRP he)) (VP (VBD sighted)))))))) (PERIOD .))