Brothers in Blood and Terrorism
COSTELLO: We first saw the killer's faces and heard their names just hours after the massacre at Charlie Hebdo. Sharif and said Kouachi, they were French brothers with Algerian roots. They were also immigrants orphanned at a young age. I want to go back to Paris and Jim Sciutto. Jim, the moment authorities revealed to the world that these were brothers, many people had this sick sense of deja vu.</s>SCIUTTO: No question. Family affair, really. The Kouachis not the first siblings to wage jihad together. Far from it, in fact. It's a pattern we've seen many times before. Our Jason Carroll has the story.</s>JASON CARROLL, CNN CORRESPONDENT (voice-over): Said and Sharif Kouachi, partners in crime, brothers who share not only blood but also an extremist ideology. But they are far from the only set of brothers who have been tied to terrorism. Boston bombing suspects Dzhokhar and Tamerlan Tsarnaev immediately come to mind. They're accused of killing three people and wounding more than 200 after detonating pressure cooker bombs at the marathon in 2013. But even before Boston, before the brothers' deadly plot, there was already a long list of siblings terrorists. Six of the 19 hijackers responsible for the attacks on 9/11 were actually brothers who worked in teams. Take the al Hazmi brothers, Nawaf and Salem. They sat together on American Airlines Flight 77 before hijacking and crashing it into the Pentagon. A year later, 2002, in Bali, three bombs, three of the terrorists were bothers. More than 200 people killed as a result. 2007 -- a failed plot. The plan this time was to attack soldiers at Fort Dix in New Jersey. Three of the would-be terrorists convicted were also brothers. Why so many siblings connections? Dr. Harley Stock is a forensic psychologist.</s>DR. HARLEY STOCK, FORENSIC PSYCHOLOGIST: Being a lone wolf self radicalizing jihadist is a hard thing to do, hard to be by yourself doing this. It's always good to have some help. The other issue is who do you trust? So obviously having a family member you can trust is helpful.</s>CARROLL (voice-over): Just two years ago here in south Florida, two men who again just happened to be brothers were charged with conspiring to use a weapon of mass destruction in the United States. Both pleaded not guilty. (voice-over): Those two brothers are Sharia and Raiz Kazi (ph). A man who would only identify himself as a Kazi (ph) brother says the allegations are not true.</s>UNIDENTIFIED MALE: I know my brothers are innocent. They never did anything wrong.</s>CARROLL: Counterterrorism experts say oftentimes even in the face of overwhelming evidence, families of the accused stick together. They say that tight family bond can be tough for investigators to break.</s>ROBERT MCFADDEN, TERRORISM EXPERT, THE SOUFAN GROUP: If you have the small group among brothers, cousins, very close friends, it makes it that more difficult for a leak to get out or to penetrate that cell with an outsider.</s>CARROLL: Experts say the tightest bond of all may ultimately be beyond blood. It is the bond of extremist ideology, the same one that drove the Kouachi brother. The same that is likely to lead more to murder. Jason Carroll, CNN, Miami.</s>SCIUTTO: A crucial investigation here not only for the authorities but the world, getting inside the minds of these extremists and finding out how and why these brothers turned to terrorism. As Jason just showed us, one that hits extremely close to home for Americans, Carol. And you know we talk a lot about influences when it comes to extremism: who influences recruits to radicalize? And it stands to reason, I suppose, that someone you know well, someone you're related to, can be sadly a likely candidate for that.</s>COSTELLO: And someone you trust, you're right. Jim Sciutto, thanks so much. The next hour of CNN NEWSROOM starts now.