(S (S (BASENP (NNS Eyewitnesses)) (VP (VBD said) (SBAR (IN that) (S (BASENP (DT the) (NN police)) (VP (VBD asked) (S (NP (NP (BASENP (NN one) (NN person)) (PP (IN in) (BASENP (DT a) (NN building)))) (SBAR (WHNP (WDT that)) (S (VP (VBD was) (VP (VBN surrounded)))))) (VP (TO to) (VP (VP (VB give) (BASENP (PRP himself))) (PRT (RP up)))))))))) (PERIOD .))