Are lone wolf terror attacks happening in U.S.?
CNN's Jim Sciutto takes a closer look at lone wolf terror attacks in the United States and the connection with ISIS.
01:45 - Source: CNN
Terror threats in the U.S. 15 videos
Nadir Soofi, left, and Elton Simpson are the two suspects in the Garland, Texas shooting.
Are lone wolf terror attacks happening in U.S.?
01:45
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- Source: CNN
Armed police  operate in Saint-Denis, a northern suburb of Paris, Wednesday, Nov. 18, 2015. Police say two suspects in last week's Paris attacks, a man and a woman, have been killed in a police operation north of the capital. Two police officers have been injured in the standoff. Police have said the operation is targeting the suspected mastermind of last week's attacks, believed to be holed up in an apartment in Saint-Denis with several other heavily armed suspects. (AP Photo/Francois Mori)
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Investigators work a crime scene before the removal a two bodies outside of the Curtis Culwell Center after a shooting occurred the day before May 04, 2015 in Garland, Texas. During the "Muhammad Art Exhibit and Cartoon Contest, " an anti-Islam event, on May 03, Elton Simpson of Phoenix, Arizonia and another man opend fire, wounding a security guard . Police officers shot and killed Simpson at the scene.
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ISIS celebrates announcement of their "Caliphate."
Caption: 	This photo was tweeted from a Twitter account widely believed to belong to ISIS in Aleppo, Province, Syria. It purportedly shows celebrating ISIS' announcement of the so called Islamic Caliphate, spanning large areas of Iraq and Syria. The Islamic State in Iraq and Syria (ISIS) is a Sunni Muslim extremist group formerly linked to al-Qaeda-- al Qaeda has since denounced ISIS.
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