(S (S (S (NP (BASENP (NN Many)) (PP (IN of) (NP (BASENP (DT those)) (VP (VBN arrested))))) (VP (VBP have) (VP (VBN been) (VP (VBN released))))) (CC but) (S (BASENP (JJ several) (NNS people)) (VP (VBP remain) (PP (IN in) (BASENP (NN custody)))))) (PERIOD .))