(S (S (BASENP (NN Transport) (NNS police)) (VP (VBD were) (VP (ADVP (RB quietly)) (VP (VBN represented) (PP (IN by) (NP (BASENP (DT a) (NN pig) (NN head)) (VP (VBG wearing) (BASENP (DT a) (NN police) (NN helmet))))))))) (PERIOD .))