We can define intertextuality as the relationship between one text and other texts. In this paper we analyze intertextuality in news reports focusing upon reporting speech, i.e. the presence of others' words in a text. We argue that when text producers choose to employ reported discourse they pursue a clear objective. Reporters may want, for instance, to detach themselves from what is said or adopt somebody else's words as if they were their own. Thus, intertextuality constitutes a powerful tool at reporters' disposal to suit their own purposes and make texts more persuasive. In the two articles on the Spanish terrorist attack from different newspapers we analyze this is highly significant because after the attack it was not certain who the perpetrators had been. However, authorship was to play a decisive role in the general elections to be held three days later: ETA's hypothesis favoured the political party in power while the fact that Al Qa'ida was behind the attack was beneficial to the opposition. In this paper we show how both newspapers, drawing mainly on the same external voices, succeed in building two different arguments and lead readers towards a biased interpretation of the facts.