(S (S (PP (IN During) (BASENP (DT a) (NN news) (NN conference))) (COMMA ,) (S (BASENP (PRP they)) (VP (VBD showed) (NP (BASENP (DT a) (NN video)) (SBAR (WHNP (WDT which)) (S (VP (VBD was) (PP (IN about) (NP (BASENP (DT an) (JJ Afghan) (NN man)) (VP (VBN arrested) (PP (IN for) (S (ADVP (RB allegedly)) (VP (VBG assisting) (PP (IN in) (BASENP (DT the) (NN attack)))))))))))))))) (PERIOD .))