(S (S (S (VP (VBG Expressing) (NP (BASENP (PRPD his) (NNS condolences)) (PP (TO to) (NP (BASENP (DT the) (NNS families)) (PP (IN of) (NP (BASENP (DT those)) (SBAR (WHNP (WDT that)) (S (VP (VBD had) (VP (VBN died) (PP (IN because) (PP (IN of) (BASENP (DT this) (NN incident))))))))))))))) (COMMA ,) (S (BASENP (JJ Mexican) (NN president) (NNP Felipe) (NNP Calderon)) (VP (VBD stated) (SBAR (IN that) (S (BASENP (DT the) (JJ federal) (NN government)) (VP (VBZ is) (S (VP (TO to) (VP (VB launch) (NP (BASENP (DT an) (NN investigation)) (S (VP (TO to) (VP (VB try) (S (VP (TO to) (VP (VP (VB establish) (NP (BASENP (DT the) (NNS identities)) (PP (IN of) (BASENP (DT the) (NNS offenders))))) (CC and) (VP (VB apprehend) (BASENP (PRP them))))))))))))))))))) (PERIOD .))