(S (S (BASENP (PRP He)) (VP (VBD said) (SBAR (IN that) (S (BASENP (NNS police)) (VP (VBP have) (VP (VBN reported) (SBAR (S (BASENP (DT a) (NN silencer)) (VP (VBD was) (VP (VBN used) (PP (IN in) (SBAR (WHNP (WP what)) (S (VP (VBZ is) (VP (VBN thought) (S (VP (TO to) (VP (VB have) (VP (VBN been) (BASENP (DT a) (VBN planned) (NN attack))))))))))))))))))))) (PERIOD .))