Salah Abdeslam, left, and his older brother Brahim have been implicated in the Paris attacks that killed 130 people in November. Brahim was killed when he set off his suicide vest in a cafe. Salah <a href="index.php?page=&url=http%3A%2F%2Fwww.cnn.com%2F2016%2F03%2F18%2Fworld%2Fparis-attack-salah-abdeslam-fingerprints-capture%2F" target="_blank">was captured in Brussels</a> on Friday, March 18. Stephen Moore, a former FBI special agent, said he is not surprised that so many terrorist cases involve brothers. Many FBI cases involved siblings, he said. "They'll support each other even when they're not ideologically sold on what you're believing in," Moore said. "They're following you, not an ideology."
Salah Abdeslam, left, and his older brother Brahim have been implicated in the Paris attacks that killed 130 people in November. Brahim was killed when he set off his suicide vest in a cafe. Salah was captured in Brussels on Friday, March 18. Stephen Moore, a former FBI special agent, said he is not surprised that so many terrorist cases involve brothers. Many FBI cases involved siblings, he said. "They'll support each other even when they're not ideologically sold on what you're believing in," Moore said. "They're following you, not an ideology."
Belgian Interior Ministry/getty images
A pair of brothers -- Khalid El Bakraoui, left, and his older brother Brahim -- are among the five people who authorities say played a part in the <a href="index.php?page=&url=http%3A%2F%2Fwww.cnn.com%2F2016%2F03%2F24%2Feurope%2Fbrussels-investigation%2Findex.html" target="_blank">terrorist attacks in Brussels, Belgium,</a> on Tuesday, March 22. They're not the only siblings who've been involved in a major terrorist attack. Two brothers sat side by side on the plane that slammed into the North Tower of the World Trade Center on September 11, 2001. Two brothers were involved in the 2013 Boston Marathon bombings. And authorities say two brothers were part of the same ISIS cell that wreaked carnage in Paris in November. What is it about brothers and terrorism?
A pair of brothers -- Khalid El Bakraoui, left, and his older brother Brahim -- are among the five people who authorities say played a part in the terrorist attacks in Brussels, Belgium, on Tuesday, March 22. They're not the only siblings who've been involved in a major terrorist attack. Two brothers sat side by side on the plane that slammed into the North Tower of the World Trade Center on September 11, 2001. Two brothers were involved in the 2013 Boston Marathon bombings. And authorities say two brothers were part of the same ISIS cell that wreaked carnage in Paris in November. What is it about brothers and terrorism?
belgian federal police
Said Kouachi, left, and his brother Cherif <a href="index.php?page=&url=http%3A%2F%2Fwww.cnn.com%2F2015%2F01%2F13%2Fworld%2Fkouachi-brothers-radicalization%2F" target="_blank">barged into the Paris offices of the satirical magazine Charle Hebdo</a> and shot down 12 people in January 2015. Both died in a shootout with police.
Said Kouachi, left, and his brother Cherif barged into the Paris offices of the satirical magazine Charle Hebdo and shot down 12 people in January 2015. Both died in a shootout with police.
French National Police/AFP/Getty Images
Two radicalized brothers, Dzhokhar and Tamerlan Tsarnaev, set off bombs near the finish line of the Boston Marathon in April 2013. Tamerlan Tsarnaev, right, was later killed in a gunbattle with police. Dzohkar, wearing the backward hat, <a href="index.php?page=&url=http%3A%2F%2Fwww.cnn.com%2F2015%2F04%2F08%2Fus%2Fboston-marathon-bombing-trial%2F" target="_blank">was convicted on 30 criminal charges and sentenced to death.</a> He is in prison awaiting appeals.
Two radicalized brothers, Dzhokhar and Tamerlan Tsarnaev, set off bombs near the finish line of the Boston Marathon in April 2013. Tamerlan Tsarnaev, right, was later killed in a gunbattle with police. Dzohkar, wearing the backward hat, was convicted on 30 criminal charges and sentenced to death. He is in prison awaiting appeals.
Courtesy Bob Leonard
Mohammed Merah, right, <a href="index.php?page=&url=http%3A%2F%2Fwww.cnn.com%2F2012%2F03%2F26%2Fworld%2Feurope%2Ffrance-shooting-suspect%2F" target="_blank">fatally shot seven people</a> in and around Toulouse, France, in March 2012. He was killed in a shootout with police. Prosecutors said Mohamed's brother Abdelkader, left, helped plan the crimes; Abdelkader is now serving a prison sentence.
Mohammed Merah, right, fatally shot seven people in and around Toulouse, France, in March 2012. He was killed in a shootout with police. Prosecutors said Mohamed's brother Abdelkader, left, helped plan the crimes; Abdelkader is now serving a prison sentence.
HANDOUT/AFP/Getty Images
Salem al-Hazmi, left, and his brother Nawaf were aboard American Airlines Flight 77, which crashed into the Pentagon on September 11, 2001.
Salem al-Hazmi, left, and his brother Nawaf were aboard American Airlines Flight 77, which crashed into the Pentagon on September 11, 2001.
fbi/getty images
Waleed al-Shehri, left, and his younger brother, Wail, were aboard American Airlines Flight 11, sitting beside each other before they helped hijack the plane that crashed into the North Tower of the World Trade Center.
Waleed al-Shehri, left, and his younger brother, Wail, were aboard American Airlines Flight 11, sitting beside each other before they helped hijack the plane that crashed into the North Tower of the World Trade Center.
FBI/getty images
Ali Ghufron, left, recruited his two younger brothers -- Amrozi, center, and Ali Imron -- to participate in the Bali, Indonesia, bombings in 2002. They detonated two bombs on the tourist island, killing 202 people from 21 different countries.
Ali Ghufron, left, recruited his two younger brothers -- Amrozi, center, and Ali Imron -- to participate in the Bali, Indonesia, bombings in 2002. They detonated two bombs on the tourist island, killing 202 people from 21 different countries.
Getty Images